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View Full Version : Sailun 80 vs. 85 size


Montana Man
03-11-2020, 10:21 AM
Because of you folks, (in a good way) I chose Sailun for our replacement tires. I have the GYs and had no issues. I did however go with the 80 series opposed to the 85. According to specs the 80 is closer in height and has a higher load rating than the GYs. I would have went with the 85s but they are an inch (half inch actual) taller.

I raised the trailer 1 1/2" with blocks to ride with the truck. That has proven to be a good move. Had I bought the 85s first I could have gotten away with 1" blocks, doh!

Any thoughts on this?

Carl n Susan
03-11-2020, 11:17 AM
I went with the 85 series and there is plenty of room for them.

jsb5717
03-11-2020, 11:42 AM
Seems to me 6 of one, half dozen of the other. I assume you went with "G" rated tires? As long as you're towing level, or close to it, then it seems like a wash.

I'm currently just shy of level and plan to move to the 85's when I buy new tires.

Golfmedik
03-11-2020, 01:31 PM
I had already bought a new set of wheels at the rally last year to put on our unit, but with all of the discussion of it going back to the factory I never did. The ones I bought are rated at #4400 each and we were going to put the 85 series Sailuns on them. Now, we'll have to wait and see as it's at the factory.

Montana Man
03-11-2020, 03:00 PM
Seems to me 6 of one, half dozen of the other. I assume you went with "G" rated tires? As long as you're towing level, or close to it, then it seems like a wash.

I'm currently just shy of level and plan to move to the 85's when I buy new tires.

We have a similar setup. Depending on your current tires, the 85s may raise the rear a bit. With my trailer 1 1/2" at the axles raised the rear 2 1/4" which was perfect. These Rams sure ride high for towing fivers.

Golfmedik
03-11-2020, 03:29 PM
Some people who are really height conscious, will go with the 17.5" wheels along with Sailun 215/75/17.5 as this combo is nearly identical to the 80 series tires with much more capacity.

CalandLinda
03-12-2020, 04:30 PM
I’m getting a lot of flack with my tire posts lately so I’m going to set the stage.

My comments here are Pros & Cons and will fall in-line with tire rules & regulations and tire industry standards. In other words, I’m not going to step over the safety line.

First off there is the question of who to seek information from when changing tire designated sizes. It’s always the vehicle manufacturer first. The following quote is from the Keystone generic 2020 owner manual.

“To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer. Look at the Tire and Loading Information label, or the sidewall of the tire you are replacing to find this information.”



A tire’s designation is a primary factor in the tire size. ST235/80R16 is a designated size. ST235/85R16 is a designated size. Because they use different load inflation charts they are not interchangeable without vehicle manufacturer approval. That approval can be predetermined when offered as a vehicle manufacturer option.

Replacement tires all fall under the same basic industry standard which says, in part, that they must provide a load capacity equal to or greater than the OE tires provided. All new – post 2007 – standards will also mention that they must be of the same designated size. ST235/80R16 a designated size with four load range numbers, D – E – F & G. Speed ratings are provided by individual brand builders.

When going up in load range, wheels & valve stems must have the ability to support the increase in Load, PSI or Both.

Keystone has always built most of their trailers with very close axle spacing. Some are so close they will not allow even the slightest increase in tire overall diameter.

When a consumer goes out on a limb and arbitrarily uses unauthorized replacements, they should know the proper procedures to follow. (The procedure is the same for authorized or unauthorized plus sized tires.) NHTSA allows auxiliary tire placards when plus sized tires do not meet the standards of a load inflation chart for the OE tires. The auxiliary placard should list the new tire size and the cold inflation pressure needed for them to provide a load capacity at least equal to the load capacity the OE tires provided. The proper location for the auxiliary placard is adjacent to the original.

Example of an auxiliary tire placard. Trailer or Light Truck tires would have load range in place of load index.

5778

rohrmann
03-12-2020, 05:36 PM
On our 2012 3402RL, it was delivered with the ST 235/80R16 load range E Marathons. After going through five of them due to various failures in less than one year we upgraded to the Goodyear G614's. This worked, as the G614's were an option from the factory, using the same wheels that the rig came with, and with the addition of metal valve stems, the tires were the answer for the tire failures with the E range Chinese tires. There is plenty of space between the tires, so this was never a question, and I'm pretty sure most Montana's come with axles spaced far enough apart to not be a problem using either the 80 series or the 85 series tires.

masterdrago
03-12-2020, 08:09 PM
I also was thinking to upsize when replacing tires. Noticed that the Sailun 17.5 come in different rim width 6" & 6.75" vs the standard 16" that are on the rig now (6.5"). Does that make any difference? I also see a reference to offset????

Montana Man
03-12-2020, 08:15 PM
I’m getting a lot of flack with my tire posts lately so I’m going to set the stage.

My comments here are Pros & Cons and will fall in-line with tire rules & regulations and tire industry standards. In other words, I’m not going to step over the safety line.

First off there is the question of who to seek information from when changing tire designated sizes. It’s always the vehicle manufacturer first. The following quote is from the Keystone generic 2020 owner manual.

“To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer. Look at the Tire and Loading Information label, or the sidewall of the tire you are replacing to find this information.”



A tire’s designation is a primary factor in the tire size. ST235/80R16 is a designated size. ST235/85R16 is a designated size. Because they use different load inflation charts they are not interchangeable without vehicle manufacturer approval. That approval can be predetermined when offered as a vehicle manufacturer option.

Replacement tires all fall under the same basic industry standard which says, in part, that they must provide a load capacity equal to or greater than the OE tires provided. All new – post 2007 – standards will also mention that they must be of the same designated size. ST235/80R16 a designated size with four load range numbers, D – E – F & G. Speed ratings are provided by individual brand builders.

When going up in load range, wheels & valve stems must have the ability to support the increase in Load, PSI or Both.

Keystone has always built most of their trailers with very close axle spacing. Some are so close they will not allow even the slightest increase in tire overall diameter.

When a consumer goes out on a limb and arbitrarily uses unauthorized replacements, they should know the proper procedures to follow. (The procedure is the same for authorized or unauthorized plus sized tires.) NHTSA allows auxiliary tire placards when plus sized tires do not meet the standards of a load inflation chart for the OE tires. The auxiliary placard should list the new tire size and the cold inflation pressure needed for them to provide a load capacity at least equal to the load capacity the OE tires provided. The proper location for the auxiliary placard is adjacent to the original.

Example of an auxiliary tire placard. Trailer or Light Truck tires would have load range in place of load index.

5778

The supplemental tire sticker is interesting. In my case, the 80 series tire is very similar in size to the original GY 85 series but with a much higher load rating. The 85 series Sailun is physically different than the original GY of the same advertised size. Manufacturers do tend to do what they want with sizing even when sizing should be standardized.

The lesson I learned is to check the manufacturers actual stated size and load rating when comparing brands.

CalandLinda
03-13-2020, 03:13 AM
The 85 series Sailun is physically different than the original GY of the same advertised size. Manufacturers do tend to do what they want with sizing even when sizing should be standardized.


Goodyear's G614 is really a bastardized tire built under the design parameters of an LT tire but with special features that led to it being called an RST (Regional Service Trailer) and limited to that service. When using the designated size LT235/85R16 it must conform to the TRA standardization charts for LT tires which is 3750# of load capacity at 110 PSI for the LRG.

The designated size, ST235/85R16 uses the TRA standard for a Special Trailer Tires which is 4400# of load capacity at 110 PSI for LRG.

Just an, Oh by the way note: Under the new RVIA 10% load capacity reserve recommendation for RV trailer tires, the GY G614 no longer qualifies for service on vehicle certified 7000# axles.

Golfmedik
03-13-2020, 04:58 AM
[QUOTE=CalandLinda;1176722
Just an, Oh by the way note: Under the new RVIA 10% load capacity reserve recommendation for RV trailer tires, the GY G614 no longer qualifies for service on vehicle certified 7000# axles.[/QUOTE]

EXACTLY!!! That is why tires like the 235/80/16 Sailun S637 with a rating of #4080 pounds has become the "standard" for 7k axles.

Dave W
03-13-2020, 06:33 AM
Axle spacing has been brought up in this and other threads as one of the ways to determine if you can use an 85 series tire. In round numbers, you are talking about a tire that is 1 inch larger in diameter vs the 80 series or put another way. 1/2" on theradius dimension PER TIRE or 1" closer together for the two tires. Looking at our HC with 33" axle spacing (some are 35"), and currently with LT 31.7" diameter85 series tires, there is still approximately 3 inches clearance.

From Sailun's site:

5540993* ST235/85R16 132/127 L 14 12 6.50 31.7 9.3 14.7 4400 3860 110
5541960* ST235/80R16 129/125 L 14 10 6.50 30.8 9.3 14.7 4080 3640 110

Montana Man
03-13-2020, 11:10 AM
That's good info, thx all! Sounds like the GYs will be phasing out from the new heavy rigs. Had I not already raised the trailer I probably would have went with the 85s in spite of slightly lowered rolling and braking efficiencies.

CalandLinda
03-13-2020, 11:41 AM
A point to remember when changing sizes from a designated ST235/80R16 to a designated ST235/85R16 is such a change is considered going to a "plus sized" tire. The tire inflation pressures and tire designated size will be invalid on trailer's certification label, in it's owner manual and on all other tire load placards.

Unless Keystone offered the "85s" as an option it's very doubtful they would approve the "85s" and tire safety wise the consumer would be out on their own limb - so to speak.

Dave W
03-13-2020, 11:44 AM
A point to remember when changing sizes from a designated ST235/80R16 to a designated ST235/85R16 is such a change is considered going to a "plus sized" tire. The tire inflation pressures and tire designated size will be invalid on trailer's certification label, in it's owner manual and on all other tire load placards.

Unless Keystone offered the "85s" as an option it's very doubtful they would approve the "85s" and tire safety wise the consumer would be out on their own limb - so to speak.


Balony - again!!!!

CalandLinda
03-13-2020, 02:13 PM
Balony - again!!!!

Where is your dissatisfaction?

This is a quote right out of the 2020 Keystone owner's manual.

"To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer."

That's a pretty straight forward quote. To top it off, ALL tire manufacturers will publish that same statement.

Dave W
03-13-2020, 04:47 PM
Where is your dissatisfaction?

This is a quote right out of the 2020 Keystone owner's manual.

"To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer."

That's a pretty straight forward quote. To top it off, ALL tire manufacturers will publish that same statement.




That is CYA wording, same as virtually eveything else you purchase in today's marketplace and as set forth by a covey of lawyers.



Thor/Keystone/Montana or any other brand does NOT give a dang what tire you use once that ownership paperwork is signed and you haul that RV off the lot. The only worry I or any other RV owner has is to maintain the bare minimum weight carrying capacity as noted on the yellow sticker. If you upgrade in size or weight capacity, that is a benefit to an RV owner. All Thor/Keystone/Montana cares about is the bottom line on their profit/loss spread sheet and that they, the manufacturer use the absolute bare minimum costwise and (hoped for) safet wise. We can challenge them on some of the crap tire used but they purportedly are of the right size and the right capacity though owners have proven that as a falicy.


Why don't we discuss brakes and their lack of capacity to safely stop a 12.000-18,000 towed RV? To me that's a lot more important. The current Montana's have exactly the same brakes right down to part number as the 1976 5th wheel I owned and that 30 footer only weighed in at about 8000 pounds. Why isn't that covered by a CYA paragraph. Isn't changing to disc brakes a non-OEM mod that affects safety in a positive manner such as added capacity brakes? Sorry, your cut and paste argumebt fails.

BiggarView
03-13-2020, 06:20 PM
How do I determine the tire inflation psi I should be inflating any tire to.

Where do I go to get that info?
So many different theories on how much air to put into your tires but no "go to" reference so anybody can make the proper calculations if needed.

Or do I simply put the maximum PSI per the tire specs and deal with whatever "ride issues" come with that psi?

Tire newbs want to know.

CalandLinda
03-13-2020, 11:43 PM
How do I determine the tire inflation psi I should be inflating any tire to.

Where do I go to get that info?
So many different theories on how much air to put into your tires but no "go to" reference so anybody can make the proper calculations if needed.

Or do I simply put the maximum PSI per the tire specs and deal with whatever "ride issues" come with that psi?

Tire newbs want to know.

The first, best place, to get information on your vehicles tire inflation pressures is in their owner's manual.

Here is a link to the 2019 Keystone owner manual. Proper tire inflation is on page #17.

https://www.keystonerv.com/media/9141971/keystone-owners-manual-2019.pdf

Remember, only the vehicle manufacturer has the authority to set the recommended tire inflation pressures for Original Equipment tires. Optional inflation pressures are at the discretion of the vehicle owner and start at what has been recommended and stop at the maximum allowed on the tire sidewall for maximum load.

It is never recommended to use inflation pressures below vehicle manufacturer recommendations for any normal conditions.

Geezertrekker
03-18-2020, 01:17 PM
Something else to consider if you put 85’s on. Most newer Montana’s are 13ft 5 or 6. Tall. Adding 2 inches height might put overall height Beyond safe for bridge clearance. Just saying

Dave W
03-18-2020, 01:43 PM
Something else to consider if you put 85’s on. Most newer Montana’s are 13ft 5 or 6. Tall. Adding 2 inches height might put overall height Beyond safe for bridge clearance. Just saying




You are adding l a half inch to the height
80s = 30.8 dia or 15.35 radius
85s = 31.7 dia or 15,85 radius

rohrmann
03-18-2020, 02:02 PM
Something else to consider if you put 85’s on. Most newer Montana’s are 13ft 5 or 6. Tall. Adding 2 inches height might put overall height Beyond safe for bridge clearance. Just saying


Typically, almost all of our 5th wheel trailers are at their highest point at the front A/C if it has one and that is where the they would be measured at. By raising the height at the tires maybe 1/2" or so won't raise the front of the rig any measurable distance. So, in short, the tires will not make any difference whether series 80 or 85 or which brand. What does make a difference is which truck you are connected to as the newer trucks seem to have higher beds and rails which is forcing the front of the trailers higher. Our 2012 3402RL connected to our 2012 Chevy measured 13'4" at the top of the front A/C. If I were to need to replace the front A/C, I would probably go with one of the newer low profile A/C units which would effectively lower the height of the rig.

bigred715
03-18-2020, 02:27 PM
We went with the '85 series also and the tire does rub on the plastic fender on the passenger side of the trailer. This happens when on a rough road and bouncing over bridges. Black marks on the front tire, right hand side. I also use the Swagman bike carrier which we have had for 10yrs and had no problem with after many miles. Don't know why you can't use on 5th wheels. It holds the bikes perfectly.

CalandLinda
03-18-2020, 03:50 PM
We went with the '85 series also and the tire does rub on the plastic fender on the passenger side of the trailer. This happens when on a rough road and bouncing over bridges. Black marks on the front tire, right hand side. I also use the Swagman bike carrier which we have had for 10yrs and had no problem with after many miles. Don't know why you can't use on 5th wheels. It holds the bikes perfectly.

You would have better off sticking with the 80s. You wouldn't have invalidated your vehicle certification with them.

Dave W
03-18-2020, 04:11 PM
You would have better off sticking with the 80s. You wouldn't have invalidated your vehicle certification with them.




Once again, BALONY!

Pathfinder75
03-18-2020, 04:20 PM
You are adding l a half inch to the height
80s = 30.8 dia or 15.35 radius
85s = 31.7 dia or 15,85 radius

bigred715; 85 series also and the tire does rub on the plastic fender"

I Wish I had gone with 85's as I wanted a little more lift to help be closer to level but feared the rub possibility hitting bumps. Had not thought about plastic fender rubbing since tire is 85%sidewall (taller) so 5% less in tread width (narrower).
I wonder If bigred715 changed rims that effected wheel offset some.

1/2" would not be much but wish I had it. I'm at 13' 0" now at Front AC unit.
Any upgrade will change how the trailer was manufactured. This is done regularly for tires, hitch pins, brakes and axles. Axle changes from 7k to 8k is common, some do the Morryde IS upgrade or just by new axles and buy one size up for safety.

CalandLinda
03-18-2020, 04:35 PM
Once again, BALONY!

Where is it?

His trailer has vehicle certified 6000# axles. The ST235/80R16 tires gave him three load ranges to chose from that would not have invalidated his vehicle certification label. LRE, LRF & LRG.

The ST235/85R16 is considered a "Plus Size" because it's larger than the OE tires, requiring the use of a different load inflation chart.

Montana Man
03-18-2020, 05:29 PM
Calandlinda, it seems you know a lot about tires. Is there some regulation you can post? I think most of us are aware about load ratings and such but if there are regs on changing sizes of tires while equaling or better the load rating, it would be helpful.

mhs4771
03-18-2020, 05:51 PM
I don't remember where I've read it, but the general rule that you can upgrade to a better/higher rated tire, but you don't want to go down.
If you couldn't go up all the folks that have moved to "G" rated or even those that went to 17.5 would all be in trouble with the Tire Police.

scottz
03-18-2020, 05:56 PM
A point to remember when changing sizes from a designated ST235/80R16 to a designated ST235/85R16 is such a change is considered going to a "plus sized" tire. The tire inflation pressures and tire designated size will be invalid on trailer's certification label, in it's owner manual and on all other tire load placards.

Unless Keystone offered the "85s" as an option it's very doubtful they would approve the "85s" and tire safety wise the consumer would be out on their own limb - so to speak.

You would have better off sticking with the 80s. You wouldn't have invalidated your vehicle certification with them.

What are you suggesting? That we are not already "out on our own"? Do you seriously think Keystone would back you in some type of tire litigation?

I could care less about "invalidating my vehicle certification"; means nothing past the date it rolled out of the factory. Besides, it would be difficult to find someone at fault because they switched to a tire with a higher load capacity.

That would be similar to saying that I "void my certification" or I am "on my own" because I upgraded from the terrible drum brakes to discs. Nonsense.

CalandLinda
03-19-2020, 01:09 AM
Calandlinda, it seems you know a lot about tires. Is there some regulation you can post? I think most of us are aware about load ratings and such but if there are regs on changing sizes of tires while equaling or better the load rating, it would be helpful.

The answers you seek is not in any single regulation. It's within the safety standards of the industry.

Without going into thousands of words that would have to be written to combine the safety regulations involved with validating my statements I'll just provide a short answer.

Even though it's not practiced in the application of RV trailer tires it is still provided in the vehicle owner manuals. "When seeking replacement tires look on the vehicle certification label for the correct size or get approval from the vehicle manufacturer for another size". By not doing that you violate a safety standard.

The proper nomenclature for a tire size is designated size. That includes the prefix, such as ST235/85R16.

When a consumer uses a replacement tire that is not on the vehicle manufacturer's approval list, such as using a ST235/85R16 to replace a ST235/80R16 you invalidate the vehicle certification label because the designated size differs. Which in the tire industry is called a misapplication.

Everything changes when the vehicle manufacturer agrees to the larger tire size. NHTSA allows the use of an axillary tire placard describing the new designated size and recommended cold inflation pressure. The axillary placard is placed adjacent to the original placard.

Load ranges and tire speed letters are not part of a designated size. Designated sizes are identical, except in internal construction, which allows the higher load range to be inflated to an increased inflation pressure to obtain more load capacity. For instance; The ST225/75R15 LRC and LRE provide identical load capacities at 50 PSI.

The USTMA writes tire industry standards in support of the standards vehicle manufacturers must follow when building your trailer. This is a verbatim quote about replacement tires. "Replacement tires should be the same as the OE size designation, or approved options, as recommended by the vehicle or tire manufacturer".

Bottom line: The vehicle manufacturer set a minimum Original Equipment tire standard when they did final certification. Within the standards, the vehicle manufacturer must comply with a statement that directs them to provide tires that are appropriate for that vehicle and set a recommended cold inflation pressure for them to provide load capacities sufficient for the certified GAWRs.

It's been my observation that RV trailer manufacturers will not approve any replacement tires that do not meet the appropriate sized they provided at vehicle certification, unless they had offered, prior to delivery optional designated sizes.

References for this post have come from FMVSS (standards), 49 CFR vehicle certification, Keystone generic owner manual and the USTMA.

CalandLinda
03-19-2020, 01:15 AM
What are you suggesting? That we are not already "out on our own"? Do you seriously think Keystone would back you in some type of tire litigation?

I could care less about "invalidating my vehicle certification"; means nothing past the date it rolled out of the factory. Besides, it would be difficult to find someone at fault because they switched to a tire with a higher load capacity.

That would be similar to saying that I "void my certification" or I am "on my own" because I upgraded from the terrible drum brakes to discs. Nonsense.

Vehicle certification rules can be found in 49 CFR part 567.

https://www.law.cornell.edu/cfr/text/49/part-567

jeffba
03-19-2020, 05:33 AM
I am getting tired from reading this thread.

bshgto
03-19-2020, 07:14 AM
I am getting tired from reading this thread.

Yeh me to....Lets argue about the Andersen hitch some more.

As far as this thread goes, Are your tires black? are your tires round? will they hold up the same weight or more than your original tires? Then your good to go. I`ve washed my camper so much I can even read my place card any more.

Theunz
03-19-2020, 08:18 AM
The only way that I could see bigger/higher capacity tires affecting the safety of a trailer is if they were considerably taller, thus raising the center of gravity. Half an inch won’t do that!

Fish
03-19-2020, 09:48 AM
Yeh me to....Lets argue about the Andersen hitch some more.

As far as this thread goes, Are your tires black? are your tires round? will they hold up the same weight or more than your original tires? Then your good to go. I`ve washed my camper so much I can even read my place card any more.

Yeah, I'm not sitting my 17000 pound trailer on those flimsy aluminum pipes, lol.

My new Hercules tires are round.

My old rainiers, well some of them weren't really round.

Camp CA
03-19-2020, 09:56 AM
Our 2020 Montana came with Saliun Radial tire ST235/80R16G and pressurized to 110 psig. They are rated for 4080 lb load. No need for taller tires since our hitch has height adjustment.

CalandLinda
03-19-2020, 12:45 PM
Our 2020 Montana came with Saliun Radial tire ST235/80R16G and pressurized to 110 psig. They are rated for 4080 lb load. No need for taller tires since our hitch has height adjustment.

And they barely provide 15% in load capacity reserves at 110 PSI. However, that's what most recommend, so keep them at 110 PSI and drive happy.

Maybe Keystone is becoming more prudent with their OE tire selections and fitments. The polyester ST235/85R16 LRF at 95 PSI would have exceeded the RVIA load capacity recommendation.

CalandLinda
03-19-2020, 01:02 PM
The only way that I could see bigger/higher capacity tires affecting the safety of a trailer is if they were considerably taller, thus raising the center of gravity. Half an inch won’t do that!

It's an industry thing. When a consumer provides their vehicle for replacement tires the tire installers are going to compare the consumer's replacement request with the vehicle certification information. To follow industry standards they can't use tires with a different size designation without vehicle manufacturer approval, it constitutes a misapplication of the replacement tires. Normally they will consult their computer files to see if their are recommendations from the vehicle manufacturer. If not they may contact them for verification.

When a consumer walks in with their wheels in hand it frees the tire installer from performing a misapplication. All they have to do is verify the wheels and valve stems can withstand the load and pressure ratings of the replacement tires and that the tires are appropriate for the wheels. The bill of sale is not going to show any vehicle identification or VIN numbers.

Fish
03-19-2020, 01:27 PM
It's an industry thing. When a consumer provides their vehicle for replacement tires the tire installers are going to compare the consumer's replacement request with the vehicle certification information. To follow industry standards they can't use tires with a different size designation without vehicle manufacturer approval, it constitutes a misapplication of the replacement tires. Normally they will consult their computer files to see if their are recommendations from the vehicle manufacturer. If not they may contact them for verification.

When a consumer walks in with their wheels in hand it frees the tire installer from performing a misapplication. All they have to do is verify the wheels and valve stems can withstand the load and pressure ratings of the replacement tires and that the tires are appropriate for the wheels. The bill of sale is not going to show any vehicle identification or VIN numbers.

I really doubt any tire installers do that.

CalandLinda
03-19-2020, 01:40 PM
I really doubt any tire installers do that.

If they are working for a well established retailer it's part of their training.

rohrmann
03-19-2020, 02:23 PM
I just got done researching old Montana brochures on the Keystone site, and since 2011, the Goodyear G614 was offered as an option using the same aluminum wheels that the E range Marathons were mounted on. The G614's only come in an 85 series, so as a point of discussion, any Montana since 2011 could have the 80 series E range tire or the 85 series G range tire until the model year 2017 when the G range tires were installed as a standard tire. The sad thing about the E range tires on these older rigs is, Keystone derated the 7,000 pound axle to 6750 lbs, just so the 3420 lb rated Marathons would be legal. With the G614's, the same axle would be fully rated to 7,000 pounds. We've been running the G614's since 2013 and have had no issues related to the tire size, and if we had not bought the rig off the lot and had ordered it, it would have been ordered with the G614 tires installed.

CalandLinda
03-19-2020, 02:45 PM
I just got done researching old Montana brochures on the Keystone site, and since 2011, the Goodyear G614 was offered as an option using the same aluminum wheels that the E range Marathons were mounted on. The G614's only come in an 85 series, so as a point of discussion, any Montana since 2011 could have the 80 series E range tire or the 85 series G range tire until the model year 2017 when the G range tires were installed as a standard tire. The sad thing about the E range tires on these older rigs is, Keystone derated the 7,000 pound axle to 6750 lbs, just so the 3420 lb rated Marathons would be legal. With the G614's, the same axle would be fully rated to 7,000 pounds. We've been running the G614's since 2013 and have had no issues related to the tire size, and if we had not bought the rig off the lot and had ordered it, it would have been ordered with the G614 tires installed.

The G614s don't meet the minimum RVIA recommendation for fitment on vehicle certified 7000# axles. It's probably why you'll start seeing the ST235/80R16 LRG or ST235/85R16 LRF as Original equipment tires on 7000# axles.

rohrmann
03-19-2020, 05:40 PM
The G614 is rated the same as the wheels, 3750 lbs at 110psi, so more tire still wouldn’t make any difference. Are the new wheels rated even higher than 3750 lbs? Even a tire rated at 4400 lbs is still only able to carry no more than the wheel weight rating.

Golfmedik
03-19-2020, 06:52 PM
The G614 is rated the same as the wheels, 3750 lbs at 110psi, so more tire still wouldn’t make any difference. Are the new wheels rated even higher than 3750 lbs? Even a tire rated at 4400 lbs is still only able to carry no more than the wheel weight rating.

That is true about the weight rating of the wheels, which is the reason I have a new set of #4400 wheels. As far as the RVIA recommendation, as funny as it sounds, only relates to the tires at 10% reserve, NOT the wheels. :eek:

CalandLinda
03-19-2020, 07:57 PM
That is true about the weight rating of the wheels, which is the reason I have a new set of #4400 wheels. As far as the RVIA recommendation, as funny as it sounds, only relates to the tires at 10% reserve, NOT the wheels. :eek:

The FMVSS requires OE tires and wheels to be appropriate for the vehicle manufacture's certified axle ratings.

rohrmann
03-19-2020, 10:15 PM
That is true about the weight rating of the wheels, which is the reason I have a new set of #4400 wheels. As far as the RVIA recommendation, as funny as it sounds, only relates to the tires at 10% reserve, NOT the wheels. :eek:

Ok, thanks. So, I’m 200 lbs shy of the 10% cushion, but that rule didn’t apply to my rig, but with axles that were derated for cheap 10 ply Marathons, I’ve got tires that give me an additional 660 lbs of weight capacity over the Marathons that came on the rig, and in over 6 years running the G614’s, I have had no issues with the tires. There was no recall on my rig to replace the tire label for the 10% rule either.

CalandLinda
03-20-2020, 09:50 AM
Ok, thanks. So, I’m 200 lbs shy of the 10% cushion, but that rule didn’t apply to my rig, but with axles that were derated for cheap 10 ply Marathons, I’ve got tires that give me an additional 660 lbs of weight capacity over the Marathons that came on the rig, and in over 6 years running the G614’s, I have had no issues with the tires. There was no recall on my rig to replace the tire label for the 10% rule either.

The RVIA recommendation has nothing to do with vehicle certification. It's just an outside of the government recommendation for it's participating members.

Remember, for all practical purposes, your axles are not certified for 7000#.

PSFORD99
03-21-2020, 02:17 PM
Well there has certainly been a lot of Koolaid drank on this thread . Good grief , run either they both will handle the load of most Montana fifth wheels . Just make sure you got the clearance. I run the Sailun 85's, a good friend also runs the 85's , we both have a slight bit of rubbing on just one fender on one tire. So that size difference could make a difference on clearance .

powerhaulic
03-22-2020, 03:16 PM
Ours came equipped with Sailuns 235/80-16G. I removed tires and installed TPMS to communicate with our new GMC for pressure and temp.
I threw the tires on the balancer out of curiosity before dismount. I was pleasantly surprised how true the tire runs, and balance was not too bad. (worst one was 3oz out)
Spending the time to do a good balance, and having nice round tires makes the towing experience more enjoyable.
Back to the real reason for my reply, when these wear or time out they will be replaced by 235/85-16 as i could raise the rear a touch for perfect leveling. We're at 5" box clearance.

Mikelff
08-09-2020, 01:05 PM
Every tire expert I have ever talked to recommended max cold tire pressure as designated on the tire. This reduces heat build up and easier roll down the road. Unless you are overloaded, I have been told by countless people including an engineer at Goodyear, this is the safest way to go. No brainer.

Mikelff
09-05-2020, 06:36 PM
As far as going to the 85’s, to get more height, you might as well stay with the 80’s and raise your rv with the lift blocks under your springs. In the long run, its a better and less expensive way to go without the tire rub. Plus, you can get the exact amount of lift you need. I have a 2018 358BH with 7000 lb. rated axles. Says that on my placard on the RV, plus there are two tags on the axles themselves. One says the axle rating is 7000lbs. and is a Keystone tag. The other is the axle manufacturer tag that states the axle is rated at 7000lbs. My axles are obviously not derated to a lower axle rating. Ok, so now tell me those ratings are wrong..... don't think so.

CalandLinda
09-05-2020, 08:50 PM
A posting recap, than I’m out of this one for good.

First is a referral back to post #7.

Misapplication; it’s a very misunderstood word with RV trailer tire applications. When reading tire warranties you’ll always find that misapplications apply to all replacement tire fitments. The basic description of a tire misapplication for RV trailers is; replacement tires must be the same designated size as the Original Equipment tires or on approval/optional recommendation by the vehicle manufacturer (An approval/recommendation only applies to the year and model number mentioned in the paperwork. You’ll also find a similar statement in your trailer’s owner’s manual under the reference “tire size”. It’s not a misapplication to add a load capacity to replacement tires of the same designated size, such as using a ST225/75R15 LRE to replace a ST225/75R LRD. Wheel PSI for the LRE must be met.

The RVIA 10% load capacity recommendation is just that, a recommendation. It has nothing to do with government regulations or standards which are unchanged. It’s just something the RV trailer manufacturers must do to stay in good standing with the large RVIA organization.

Wheels that provide a load capacity and PSI rating of a replacement tire with more load capacity than the OE tires don’t have to be changed. Wheels are only required to carry the load of the vehicle certified GAWRs. Not overloading the GAWRs is an owner’s responsibility.

When modifications for lifting your trailer are performed, it’d be a good idea not to exceed the maximum height allowed in the state of registration.

Remember: The information on the vehicle certification label, once transferred to a consumer, can only be changed by the vehicle manufacturer or a certified vehicle modifier.

I feel compelled to insert this one statement from FMVSS 571.120 paragraph S5.3.1 Tires. The size designation and the recommended cold inflation pressure for those tires such that the sum of the load ratings of the tires on each axle is appropriate for the GAWR. That's the bottom line, minimum requirement and is found on the vehicle certification label.

Just in case you don’t want to look it up, here is a verbatim quote from the Keystone generic owner’s manual (page #21).

Tire Size:

“To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer. Look at the Tire and Loading Information label, or the sidewall of the tire you are replacing to find this information. If you have any doubt about the correct size to choose, consult with the tire dealer.”

My reference materials: FMVSS (standards) – USTMA standards manual for RVs – Keystone owner’s manual.

RMcNeal
09-06-2020, 03:52 AM
I know this horse has been dead a while, so I won't beat it any more. Just a quick question about the Keystone owner's manual. It says-
“To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer."
Is that the tire manufacturer or trailer manufacturer? Isn't Keystone the latter?

Mikelff
09-06-2020, 12:49 PM
I know this horse has been dead a while, so I won't beat it any more. Just a quick question about the Keystone owner's manual. It says-
“To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer."
Is that the tire manufacturer or trailer manufacturer? Isn't Keystone the latter?

Yes, that would be Keystone/Montana.

Mikelff
09-06-2020, 01:07 PM
For a set of Sailun 85’s, they are about $60 for four, more that the 80’s. For less than $150 you can lift your trailer at the springs . If you do it yourself, less than that. There are threads in the forum that cover this topic with pictures. No tire rub, ever. Seems to me its a safer and inexpensive way to go vs. going to 85’s for an inch or two of lift. Just me!

Mikelff
09-06-2020, 01:13 PM
A posting recap, than I’m out of this one for good.

First is a referral back to post #7.

Misapplication; it’s a very misunderstood word with RV trailer tire applications. When reading tire warranties you’ll always find that misapplications apply to all replacement tire fitments. The basic description of a tire misapplication for RV trailers is; replacement tires must be the same designated size as the Original Equipment tires or on approval/optional recommendation by the vehicle manufacturer (An approval/recommendation only applies to the year and model number mentioned in the paperwork. You’ll also find a similar statement in your trailer’s owner’s manual under the reference “tire size”. It’s not a misapplication to add a load capacity to replacement tires of the same designated size, such as using a ST225/75R15 LRE to replace a ST225/75R LRD. Wheel PSI for the LRE must be met.

The RVIA 10% load capacity recommendation is just that, a recommendation. It has nothing to do with government regulations or standards which are unchanged. It’s just something the RV trailer manufacturers must do to stay in good standing with the large RVIA organization.

Wheels that provide a load capacity and PSI rating of a replacement tire with more load capacity than the OE tires don’t have to be changed. Wheels are only required to carry the load of the vehicle certified GAWRs. Not overloading the GAWRs is an owner’s responsibility.

When modifications for lifting your trailer are performed, it’d be a good idea not to exceed the maximum height allowed in the state of registration.

Remember: The information on the vehicle certification label, once transferred to a consumer, can only be changed by the vehicle manufacturer or a certified vehicle modifier.

I feel compelled to insert this one statement from FMVSS 571.120 paragraph S5.3.1 Tires. The size designation and the recommended cold inflation pressure for those tires such that the sum of the load ratings of the tires on each axle is appropriate for the GAWR. That's the bottom line, minimum requirement and is found on the vehicle certification label.

Just in case you don’t want to look it up, here is a verbatim quote from the Keystone generic owner’s manual (page #21).

Tire Size:

“To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer. Look at the Tire and Loading Information label, or the sidewall of the tire you are replacing to find this information. If you have any doubt about the correct size to choose, consult with the tire dealer.”

My reference materials: FMVSS (standards) – USTMA standards manual for RVs – Keystone owner’s manual.

I agree. Better to go with a lift at the springs. Keep your 80’s and not worry about tire rub. You can get a much better result and have the lift you need, as long as it’s not excessive.

Ram Montana High Country
09-06-2020, 06:21 PM
I agree. Better to go with a lift at the springs. Keep your 80’s and not worry about tire rub. You can get a much better result and have the lift you need, as long as it’s not excessive.

Tire Rub - I've not had tire rub on either unit ... this is the first I've heard of rub.

Mikelff
09-06-2020, 07:03 PM
Tire Rub - I've not had tire rub on either unit ... this is the first I've heard of rub.

Somewhere in the above posts they talk about a tire rubbing a fender or fender well.

Twopetes
09-07-2020, 06:34 AM
Sailun 85’s for 4 years, No rubbing and compared to the original Westlakes, the Sailuns are great!. I am looking at my tires right now and I have no space issues. The extra 1/2” in net height is not an issue.

Putting a safer tire on my rig in my opinion just makes sense. Kind of like the disc brake upgrade I just completed. The real question is why don’t the mfg’s do it.

And regarding trailer height, I would be more concerned with the taller bed heights in the newer model trucks. Adding 4-5 inched to the hitch height not only changes the way the trailer sits on the wheels, it adds to the overall height for clearance.

fatcatzzz
09-07-2020, 07:49 AM
Sailun 85’s for 4 years, No rubbing and compared to the original Westlakes, the Sailuns are great!. I am looking at my tires right now and I have no space issues. The extra 1/2” in net height is not an issue.

Putting a safer tire on my rig in my opinion just makes sense. Kind of like the disc brake upgrade I just completed. The real question is why don’t the mfg’s do it.

And regarding trailer height, I would be more concerned with the taller bed heights in the newer model trucks. Adding 4-5 inched to the hitch height not only changes the way the trailer sits on the wheels, it adds to the overall height for clearance.

:iagree::iagree:

Two sets of 85's and all most 50000 miles NO rub, not even close.

Dave W
09-07-2020, 08:13 AM
:iagree::iagree:

Two sets of 85's and all most 50000 miles NO rub, not even close.


Nary a problem with our HC in 28K miles with 85s. Less then 1/2" on the radius and both the 80 and 85 series tires have a 9.3" section width. So, where does a rub come into play?



Of course that will be trolled by a tire 'expert'

prndl
09-07-2020, 09:24 AM
85's and some DS rubbing, not a big deal.

Tom N OH
09-15-2020, 05:15 PM
Sailun 85’s for 4 years, No rubbing and compared to the original Westlakes, the Sailuns are great!. I am looking at my tires right now and I have no space issues. The extra 1/2” in net height is not an issue.

Putting a safer tire on my rig in my opinion just makes sense. Kind of like the disc brake upgrade I just completed. The real question is why don’t the mfg’s do it.

And regarding trailer height, I would be more concerned with the taller bed heights in the newer model trucks. Adding 4-5 inched to the hitch height not only changes the way the trailer sits on the wheels, it adds to the overall height for clearance.

OMG! YOU CAN’T DO THAT! Anything other than what the sticker says will upset the whole balance of the Earth! Great. Now we will all be facing the Apocalypse. Thanks a lot. (Sarcasm)

CalandLinda
09-15-2020, 06:24 PM
OMG! YOU CAN’T DO THAT! Anything other than what the sticker says will upset the whole balance of the Earth! Great. Now we will all be facing the Apocalypse. Thanks a lot. (Sarcasm)

In my opinion, when a consumer blatantly defies expert information, they are setting themselves as a more competent expert. As such, they should provide references to their expertise.

Just a muse, what do you think?

PSFORD99
09-15-2020, 06:39 PM
85's and some DS rubbing, not a big deal.

Same here just some slight rubbing with the Sailun 85's, same spot as yours on one tire. I agree not a big deal .

PSFORD99
09-15-2020, 06:55 PM
Nary a problem with our HC in 28K miles with 85s. Less then 1/2" on the radius and both the 80 and 85 series tires have a 9.3" section width. So, where does a rub come into play?



Of course that will be trolled by a tire 'expert'

You see the picture above ,hopefully that explains any of your doubts . I replied above ,I have the same rub spot as the picture. A friend ,and neighbor with a Montana, with Sailun 85's has one tire rubbing slightly same as the picture ,and the same as mine.

The tires are 1" taller ,you gain 1/2" everywhere, you are 1/2" closer to the plastic wheel well moldings , you hit a bump the tire come ups, and closes that gap on the curve of the molding , pretty simple to figure out . Makes no difference on section width ,unless they were wider ,and rubbed on the inside . But they are rubbing when hitting a bump its obvious. Some do ,some don't . I know of three that do . You are apparently one that doesn't .

Not a tire expert ,nor a troll, but you needed to get set straight.

CalandLinda
09-15-2020, 06:56 PM
In general, Keystone RV trailer axles are spaced to provide safe operation of the original equipment tires and any vehicle manufacturer optional sizes.

That spacing provides safety clearances between tires and in the wheelwell.

When the trailer becomes the property of a consumer, that consumer becomes' its safety expert.

The primary overseer of vehicle safety will be the state or province where the vehicle is operated.

PSFORD99
09-15-2020, 07:02 PM
In my opinion, when a consumer blatantly defies expert information, they are setting themselves as a more competent expert. As such, they should provide references to their expertise.

Just a muse, what do you think?


I think putting on 85's ,and a higher weight rating is a good thing. As long as the wheels handle 110 psi. What do you say.

I have no expertise ,but why don't you let us know the issue with 85's over 80's forget what the placard says, what are the issues . Tire failure ,axle failure ,brake failure, wheel failure etc etc etc . Will I be arrested ?, we need to know. :hide:

CalandLinda
09-15-2020, 07:15 PM
I think putting on 85's ,and a higher weight rating is a good thing. As long as the wheels handle 110 psi. What do you say.

I have no expertise ,but why don't you let us know the issue with 85's over 80's forget what the placard says, what are the issues . Tire failure ,axle failure ,brake failure, wheel failure etc etc etc . Will I be arrested ?, we need to know. :hide:

The 85 is wider and taller than the 80. Will the us of the larger tires get vehicle manufacturer approval? your owner's manual suggests you ask them.

ChuckS
09-16-2020, 07:04 AM
Took off the OEM 235/80x16 tires a few months after purchase and replaced with 235/85x16 24 ply... it raised overall height 1/2 inch which is not a factor at all...and hasn’t been for the last 7 years...

The increased load capacity from 235/80 tp /85 series is a smart and wise move... there are no suspension clearance issues on my fifth wheel and could care less what the sticker outs8de says.. never read it nor will I...

CalandLinda
09-16-2020, 07:40 AM
Took off the OEM 235/80x16 tires a few months after purchase and replaced with 235/85x16 24 ply... it raised overall height 1/2 inch which is not a factor at all...and hasn’t been for the last 7 years...

The increased load capacity from 235/80 tp /85 series is a smart and wise move... there are no suspension clearance issues on my fifth wheel and could care less what the sticker outs8de says.. never read it nor will I...

Well, you don't have to read the placard. When you went with the 85s it invalidated the placard.

PSFORD99
09-16-2020, 08:21 AM
Well, you don't have to read the placard. When you went with the 85s it invalidated the placard.

You are totally missing the point here, as said lets forget the placard , thats a CYA for the manufacturer . If they really cared about the issues with their tires to begin with ,we wouldn't be having this conversation ,so why even bother bringing up the placard .

Lets get back to the question ,what is the issue that you have with replacing the 80's with 85's, I see none unless there is a clearance problem. There are two advantages that I know of, it raises the fifth wheel to help a little with leveling . With today's trucks they just keep getting higher. But most importantly they increase weight rating provided as said the wheels are rated for 110 psi.

mhs4771
09-16-2020, 09:27 AM
I have no Horse in this race, but I remember a long time ago that a Tire Dealer could not put a lesser tire on than what was dictated by the vehicle tire placard. So as long as the replacement tire was equal to or better everything was fine.
If putting larger or better tires on a vehicle is wrong then half of the vehicles on the road are illegal because they're running over sized or better grade of tire.
Thinking that putting on a BETTER tire is wrong just doesn't make any sense to me.
Enough said!

PSFORD99
09-16-2020, 09:34 AM
I have no Horse in this race, but I remember a long time ago that a Tire Dealer could not put a lesser tire on than what was dictated by the vehicle tire placard. So as long as the replacement tire was equal to or better everything was fine.
If putting larger or better tires on a vehicle is wrong then half of the vehicles on the road are illegal because they're running over sized or better grade of tire.
Thinking that putting on a BETTER tire is wrong just doesn't make any sense to me.
Enough said!


If only it were that easy ,as enough said. But yes I agree .

BiggarView
09-16-2020, 11:25 AM
....
Thinking that putting on a BETTER tire is wrong just doesn't make any sense to me.
Enough said!

Who said the 85 series was a better tire except subjectively. It's just a different tire. Would it not be up to the mfr or regulatory authority to say it was actually better the OEM spec? just throwing gasoline on this fire:whistling::hide:

vacationer
09-16-2020, 11:42 AM
just put 85,s on wrote over the placard in black marker works great. lol:lol:

CalandLinda
09-16-2020, 01:10 PM
This is always beaten to death. Mostly that’s because those that argue for the use of the plus sized tire over the certified tire are oblivious of safety regulations and industry standards.

The Federal vehicle certification label affixed on every vehicle built under the guidance of FMVSS (standards) is mandatory. The information on it are minimums.

The key word in the selection process for OE tires is Designated Size. Vehicle manufacturers have the sole responsibility in the selection, fitment and setting recommended cold inflation pressures that are appropriate for those fitments.

Tire size designations are not interchangeable unless they are approved, recommended or offered as options by the vehicle manufacturer.

Size designation systems presently in use:

• P-Metric
• Metric (a.k.a. Euro-Metric)*
• LT-Metric
• LT High Flotation
• LT Numeric
• European Commercial Metric (C-Type)*
• ST Special Tire for Trailers
• T-Type Temporary Spare

Size designations usually include letters which have the following meanings:

• P = P-Metric (Passenger)
• LT = Light Truck
• C = European Commercial (Light Duty)
• ST = Special Tire for Trailers
• T = Temporary Spare
• R = Radial Construction
• F = Self-Supporting, Runflat
• D = Diagonal (Bias) Construction
• B = Belted Bias Construction

ST235/80R16 is a designated size
ST235/85R16 is a designated size
LT235/85R16 is a designated size

Montana Man
09-16-2020, 03:28 PM
Thanks CalandLinda for the information. It is good to know about the legalities. At least we can't say we didn't know. Much like overloading 3/4 ton trucks with our Montys. We all live with life decisions we make.