What tire pressure for load range G tires?

[David and Jo-Anna]

I had all of my Mission tires replaced today with Goodyear G614 LT235/85R16 Load Range G tires. During the changeout, we found another of the Mission tires that was starting to show evidence of the tread separating from the belts. Even though it was expensive, I'm feeling a lot of peace of mind having those Missions off our rig.

Had a lengthy discussion with the service manager at Wingfoot Commercial Tire about the proper inflation pressure to go with since my tires were probably only seeing a load of 3000# per tire. The max load rating for these load range G tires is 3,750# at 110 psi. The service manager took the position that, "based on his 17 years in the tire business", he would strongly recommend inflating the tires all the way up to their 110 psi rating as that would diminish how hot the tires would get when traveling down the road. He said I would not likely see any unfavorable wear on the tires since they weren't really "overinflated" since they were only at their rated pressure. I told him that, according to the Goodyear tire load sheet I had seen on line, I should only be inflating my tires to around 80-85 psi for a load of 3000# per tire. He then called the tech rep at Goodyear who confirmed that the tires would wear better if inflated to 110 psi even though the load was only 3000# per tire.

Are these guys correct, or should I follow the on-line load rating sheet? What's the downside risk of going with 110 psi?

[8.1al]

David,
I think you were given good advice. Although the tires will be overinflated in regards to the load, you'll never wear them out. The only downside I can think of is the trailer will see a harder ride. If you are uncomfortable with placing the max pressure on tires and wheels, how about 100psi. This will give you plenty of safety factor all the way around.

[Delaine and Lindy]

David I ran those same tires on our Cambridge Goodyear G614's. They came standard on our Cambridge. Really think Keystone should step up to the G614 on the heavy Montana's. I also ran them at 110 lbs as the side wall says. They always ran cool, never got hot. I am now looking at the 614's for our new 5er (SOB) because it has a tire called Freestar? However its a G rated tire, I still will not run a China made tire. The problem I'm having is cost, last quote was $227.00 + balance. But I'm still shopping. If you don't mind what did you pay. Good Luck.... GBY...

P.S. I have Missions on my 32' inclosed Hallmark car trailer.
However I don't run it very often, I just use it for storage.

[mail2us]

Where are the Goodyear 614's manufactured?

[Mike Boutet]

The tires are made in the US. Just be sure that the rims are capable of handling 110psi. If they can then run them at 110.

[David and Jo-Anna]

I paid $229 each for my G614s, plus the usual mounting and balancing charges and, of course, taxes. More than it would have cost for several of the alternatives I looked at, but after having one Mission tire lose its tread and another close to it, it's worth the peace of mind I now have with the
614s on the rig.

And they are MADE IN THE USA!!!!!!

[firetrucker]

IMO, and Goodyear's website, you are "overinflating" your tires for the load. Yes, they will run cooler because there is less rolling friction and flex, but there is also less rubber contact with the road (smaller footprint). You will probably see increased wear in the center of the tread. Since tires fundamentally act like springs, the ride will be harsher. Remember the Firestone problem? That was mostly because tires were not inflated to the manufacturer's recommendations. Will you get away with it? Probably, because most people do. But at least measure the load on each tire so you know the weight distribution. That might surprise you.

Bob

[bsmeaton]

I'm trying to figure out how running these at 110 psi is overinflating when most of our trucks are running the full 80 psi with an empty bed.

I've always felt comfortable that running up to the maximum is always a safe option, but running down to the minimum pressure per the chart is also acceptable if desired to "soften" the ride.

I would think both answers are right.

[Broome101]

My G rated state right on side wall 110 PSI

[LonnieB]

First of all, what I am about to say is not intended to offend anyone, nor is it intended to start an argument. I just feel it is my responsibility as a tire dealer to shed some light on this subject.

Goodyear, Bridgestone, Firestone, Michelin, BF Goodrich.........etc, all spend millions of dollars through their R&D departments testing and gathering information on their tires. They put their tires through everything imaginable, from improper inflation, to overloading, to running across molten asphalt. They test their tires to the point of failure, even total destruction. This is how they determine the safety, and longevity of the tires, and this is how they come up with the information published on their charts. They will not knowingly publish any information that would lead to premature tire wear, or failure. They publish these charts for the safety and well being of the end user who drives all over the country at 55 to 85 miles per hour on approximately 200 square inches of cantact area where the "rubber meets the road".

The max load, and max inflation numbers molded on the sidewall of the tire mean exactly what they say, maximum inflation the tire can safely withstand at the maximum load the tire can safely withstand. This does not mean the tire must be inflated to the maximum pressure at all times to be safe, it only means the tire must be inflated to maximum in order to safely carry the maximum load molded on the tire. The max load on my truck tires is 3415 pounds at 80 psi. I keep the front and rear at 60 psi, and depending on which trailer I am towing, adjust the rear accordingly.

As a tire dealer, and an end user, I recommend following the load/inflation index published by the company that manufactured your tires.

[8.1al]

Well said Lonnie, thanks

[mail2us]

Lonnie,

what is your input on the Goodyear G614 LT235/85R16 Load Range G discussed?
If you are uncomfortable with posting a thread, send me a PM.I have the Mission RV tires on our new 3400. I am not at all knowledgeable about RV tires other than what I've been reading here. Dennis

[LonnieB]

Dennis, the Goodyear G614 is an excellent tire. The only problem I have encountered with them is price (they are expensive), and availability. The availability issue is getting better, but the cost will keep going up.

[bigmurf]

Lonnie: Thanks, now if people would only weight EACH tire.

[bsmeaton]

Why would somebody weigh their tires?

[LonnieB]

Brad,

I believe he's talking about weighing the load on each individual tire to determine the correct psi per tire. This would be the ideal way to determine psi needed, but time consuming, and troublesome to the point it's not feasable in most cases.

[bsmeaton]

Aaah - Thanks Lonnie. I actually helped the tire shop drag some of those G rated tires out to my last rig, and they were heavy tires - thought maybe there was a GVWR concern! hahahahaha

[mail2us]

Thanks Lonnie for your reply. You gotta be a good tire store manager cause you're near Lubbock!! hehehe

[MacDR50]

My approach to tires is ((GVWR-(GVWRx15% 0r 20%))/4)x1.15. This is "MY" thinking and I not suggesting it is expert. I did a lot of research but that's how I make up my mind about these things. Everyone has to do what they feel gives them the degree of comfort they they will accept.

For my new 3585SA GVWR is 15,325#, 15-20% of this is a realistic Pin weight leaving the tires carrying 12,260# - 13,026#. Each tire theoretically carries 1/4 of this or 3,065# - 3,256#. I then add a 15% safety margin to account for uneven loading, wind list, road camber, cornering, aging and a bit of carrying extra weight should I loose some pressure in the other tire on the same side. That gives me a tire load requirement of 3,524# - 3,745#. Using the Goodyear Load & Inflation tables, the G614 LT235/85R16 tire, which is marketed as a trailer tire with a speed rating of 75 MPH, will support 3550# at 100PSI. Both tire and aluminum rim will accept 110PSI cold inflation to give 3,750#. If I drop the inflation pressure to 95PSI, max load drops to 3,415# or below my targeted "I feel SAFE" requirement for 20% Pin weight but still well above the actual "Average" load that the tire will carry at that Pin weight. So now I have a tire that gives me a wide range of inflation pressures to match varied loading with a healthy safety margin.

I know I looked at the specs on the new 2008 models with the (GY Marathon??) ST 235/80R16 and posted them in another thread but now can't find the post. If anyone can confirm the tire used on the new 2008's I'll see if I can locate the load information again. The Marathon tire is listed in the GY site for 3000# at 65 PSI. The original Missions were good for 3,520# at 80PSI. Both the Mission and Marathon tires are rated at their respective max loads for a maximum speed of 65MPH.

Hope this helps further this thread. I say again I can't say my way is the right way but it works for me.

[skypilot]

Just to add my .02 worth -- on MY Dodge 3500 DRW I've had to lower my rear tire pressures to 35 to 40 psi when running empty just to quit wearing the center rib out on the tires -- at 35 to 40 (not exactly sure what I have it in today due to weather / temp change but I'm now getting the entire rear tires to make contact (less the slightest little bit on the very edges. Wear is much better and hopefully the tires will last better.

That said, my front tires are at 65 psi at all times with the diesel engine weight on them. (An interesting aside, my 04.5 Dodge said to run 65 / 65 all tires; my 06 has a 2nd placard that says to run 65 / 40 light, 65/65 when loaded...)

On my 5th wheel I ran 110 psi on all tires running the GY 614s. The dealer has told me to lower the pressure some to soften the ride -- I've had some shelving damage caused by the rough roads and the dealer says the tires were too stiff and transmitting too much to the coach -- this even with TrailAir suspension and hitch pin!!! Have not had the unit back on the road since lowering the pressure except to bring it home from the dealer following repair. Will keep an eye on it though.