Sailun 80 vs. 85 size

[Montana Man]

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]

I went with the 85 series and there is plenty of room for them.

[jsb5717]

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]

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]

Originally Posted by jsb5717

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]

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]

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.

[rohrmann]

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.

[Montana Man]

Originally Posted by CalandLinda

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.

Attachment 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.

[ForBruce]

Originally Posted by jsb5717

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.

just shy of level to the rear helps to keep pin weight down.... that might matter with SRW

[Keith Schweizer]

Maybe kind of a " dumb" question, but when ordering tires from say Simple Tire. Where does one go to have their tires mounted? Tire shop I know.
Will any tire center be willing to install a tire that was not purchased from them? The reason I ask is because I purchased 4 Bilstein shocks for my truck and when I went to Big O they wanted to charge me double the normal price for installing a shock. I asked a local Walmart tire center if they carried Sailun tires and they told me NO. Yet I have seen Sailuns on their website??

[PSFORD99]

That’s where I bought my Sailuns , Walmart . At the time they were cheaper then Simpletire , and free shipping. Had a local tire shop I deal with mount and balance them . They had no problem with It , matter of fact I gave them an opportunity to price match , which they had done in the past , but didn’t this time .

[masterdrago]

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????

[Camp CA]

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]

Originally Posted by Camp CA

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.

[Montana Man]

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]

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]

Originally Posted by CalandLinda

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]

Originally Posted by Dave W

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]

Originally Posted by CalandLinda

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.