Montana Owners Club - Keystone Montana 5th Wheel Forum - View Single Post - Is there a ride differrence in LR D and E tires?

Glenn and Lorraine · 07-18-2005, 02:54 PM

Glenn, you were one of the ones I was referring to when I said 'tire experts.' Thanks for replying. The tires are ST235/80R16 LR D Goodyear Marathon. On the sidewall they say max 3000 lbs at 65 psi.
Thanks Steve and Your Welcome but I am far from an expert. I haven't dealt with tires for a living for over 15 years. Most of my replys have been really testing my memory.

Does it hurt to run them at max even if not at max load? I always figured that way if they lose a little pressure for whatever reason I would likely catch it before they became underinflated for the load.
Actually Yes it does. You would be better off checking the pressures every so often than running them over inflated.
If your tires are overinflated by as little as6 psi, they could be damaged more easily when running over potholes or debris in the road. Higher inflated tires cannot isolate road irregularities well causing them to ride harsher.
When you over inflate you cause the center of the tread area to push out. This creates a problem of premature tire wear down the center of the tread area. Also it lessons the area of tread contact with the road. Less road contact equals less braking power.
An additional note--under inflation causes tread wear on the shoulders of the tire.

Total weight on the axles is 11060. I did not, unfortunately, weigh each axle separately nor each wheel separately, which should be done to determine best pressure, right?
Ideally yes knowing the load on each tire is definitely the best but realistically, as there should not be any significant difference, knowing the total weight on both axles and dividing by 4 will be just as effective.

Interestingly, the table in the link you provided, Glenn, shows a max speed rating of 65 mph on the ST tires. That's the first time I've ever heard about a speed rating on these tires. That should be a more prominent piece of information, I should think.
Now you have entered an area that I can't really help with. We did very little business with trailer tires and to be honest in my day I'm not sure there even was an "ST" designation. I did a search on "tire speed rating" but could not find any helpful info.

07-18-2005, 02:54 PM	#9
Glenn and Lorraine Montana Master Join Date: Jul 2003 Location: Clearwater Posts: 10,917 M.O.C. #420	Glenn, you were one of the ones I was referring to when I said 'tire experts.' Thanks for replying. The tires are ST235/80R16 LR D Goodyear Marathon. On the sidewall they say max 3000 lbs at 65 psi. Thanks Steve and Your Welcome but I am far from an expert. I haven't dealt with tires for a living for over 15 years. Most of my replys have been really testing my memory. Does it hurt to run them at max even if not at max load? I always figured that way if they lose a little pressure for whatever reason I would likely catch it before they became underinflated for the load. Actually Yes it does. You would be better off checking the pressures every so often than running them over inflated. If your tires are overinflated by as little as6 psi, they could be damaged more easily when running over potholes or debris in the road. Higher inflated tires cannot isolate road irregularities well causing them to ride harsher. When you over inflate you cause the center of the tread area to push out. This creates a problem of premature tire wear down the center of the tread area. Also it lessons the area of tread contact with the road. Less road contact equals less braking power. An additional note--under inflation causes tread wear on the shoulders of the tire. Total weight on the axles is 11060. I did not, unfortunately, weigh each axle separately nor each wheel separately, which should be done to determine best pressure, right? Ideally yes knowing the load on each tire is definitely the best but realistically, as there should not be any significant difference, knowing the total weight on both axles and dividing by 4 will be just as effective. Interestingly, the table in the link you provided, Glenn, shows a max speed rating of 65 mph on the ST tires. That's the first time I've ever heard about a speed rating on these tires. That should be a more prominent piece of information, I should think. Now you have entered an area that I can't really help with. We did very little business with trailer tires and to be honest in my day I'm not sure there even was an "ST" designation. I did a search on "tire speed rating" but could not find any helpful info.