Forum Discussion

kzspree320's avatar
kzspree320
Explorer
Jun 03, 2017

Can tires have too much reserve capacity?

I had a blowout on my way home on Memorial Day. I had gone over 1,800 miles of our 2,000 mile trip and was getting close to home. Rear tire on passenger side blew. Got the estimate yesterday and damage about $3K. I never want this to happen again. I had checked the tire pressure and it was 77 psi (max 80) right before we left for home. Tire was a Goodyear Marathon 235/80/16 E rated tire with stated capacity of a little over 3,400 lbs.

Info on my fifth wheel is GVWR of 13,940# with 2 axles each rated for 6,000 lbs. Add the pin weight and you get to the GVWR. The E rated tires should be enough since the 2 tire ratings per axle are over 6,800 lbs. I want all new tires and am willing to spend to get good ones. My fifth wheel is a 2014 so my tires are not old but I just want all good rubber.

I see 2 decent options. Get the Michelin XPS Ribs or the Duravis r250 size 235/85/16. I have enough space so that's not a problem. The tires are only rated for 3,042 each, which is enough if both sides weigh the same, but I doubt that's the case. I normally weigh abut 12,500 ready to camp. Subtract pin weight and estimate 10,000 lbs on axles. That's just 2,500 lbs per tire if they are all equal, which I seriously doubt since the heavier appliances and reclining love seat are in one slide out on the same side as the bedroom slide. I actually think the tire that blew was on the light side of the camper.

The other option is to go to the Sailun S637 G rated tires with a rating of about 4,000 lbs per tire. Sure seems like overkill but maybe not. My rims are rated for 3,980 lbs and 110 psi (stamped inside rims). Seems like I could run about 100-105 psi and hopefully never have a blowout.

My question is this, "can you have too much reserve capacity on tires?" Would the stiffer tires place too much stress on the remainder of the suspension system, since a E rated tire might absorb more stresses than a G rated tire would.

I know there are a million of these tire threads and I have read most of them. All thoughts and opinions on this subject is welcome and appreciated. I need to make a tire decision soon. Thanks. Keith
  • For a 14K GVWR, I would get the Sailuns since you have the high psi wheels.
  • OP back to answer some comments

    corvettekent wrote:
    You should put your trailer on a CAT scale and see what the weight really is.
    I have. When I said the trailer axles carry 10,000 of the 12,500 lbs,, it is because the CAT scales gave the trailer axle weights as 9,980 previously. I was probably loaded to within 200# of that. The CAT scales did not give me the weight per side or per tire.

    I must admit I have considered a TPMS system for the fiver, but I had not pulled the trigger yet. Would it have made a difference? Possibly depending on the cause. I can certainly see one in my future now.

    Some things I forgot to post that have been mentioned - 1) I always tow at no more than 65 mph. No excess speed caused it. 2) The temperature when it happened was 79 degrees. It's not like it was hot that day. Not your typical 96 degree summer day in this area.

    There are a lot of good comments and I appreciate them. Nice to now others with 14K GVWR fivers that probably are speced for E rated tires have gone to G rated tires with no problems.

    Thanks for all the comments and keep them coming.
  • Hi,

    Tires do sometimes fail. But I wonder if you did not get a puncture which caused a slow leak which led to overheating and *bang*.

    I have a tire pressure monitoring system for my peace of mind. On a day where it is 79f, my rear inside dual tires go up from 80 lbs to 97 lbs if I drive for 2 hours.

    kzspree320 wrote:
    Some things I forgot to post that have been mentioned - 1) I always tow at no more than 65 mph. No excess speed caused it. 2) The temperature when it happened was 79 degrees. It's not like it was hot that day. Not your typical 96 degree summer day in this area.
  • If you kept the bad Goodyear tire, they will cover the damage as well as a replacement tire. I have done it many times prior to me replacing them with 17.5" wheels and tires. Go to a Goodyear dealer and they can generate the proper paper work and get your claim started.
    Good luck,
    Catfish
  • j2catfish wrote:
    If you kept the bad Goodyear tire, they will cover the damage as well as a replacement tire. I have done it many times prior to me replacing them with 17.5" wheels and tires. Go to a Goodyear dealer and they can generate the proper paper work and get your claim started.
    Good luck,
    Catfish


    And most likely sell them a set of GY "G" or the new Endurance tire for a great price.
  • Your Columbus 295RL, is very near the weight of our Mountaineer. We took the Marathons off immediately, put on a set of 2 year old BFG's that we took off the last trailer. Got almost 2 years more out of them before changing to the R250's The R250 are now 4 years old, zero issues. I too have thought about going to the Sailuns, and have 110 psi rims. But I'm at a good weight for the R250, and the Sailun would be run well under max inflation.
  • Lantley wrote:
    jjj wrote:
    One other issue are those marathons made in CHINA. I would not put another china tire on my rig even if it had the goodyear name on it.

    Sailun's are made in China. They are on of the best, if not the best RV tire made.


    Yes they are but they just recently changed their tires to a better standard of compound. Time will tell if they are the only reliable china tire.