Forum Discussion

Effy's avatar
Effy
Explorer II
Mar 05, 2014

tire pressure - again

I know, I know, this has been brought back more times than the living dead. My question is very simple. My tires on my 16k# coach are Goodyear g670s. I like them. The sticker inside says to run them at 83 psi. And I do. But the ride is rough. Smooth on smooth roads but hit a pothole or concrete road and the feedback will rattle your teeth. My coach is light and in talking with my dealer he says I can run as low as 75 psi to soften it up. Looking at Goodyear’s rating table, there is a marginal difference in weight at the wheel between 85 and 75 PSI. Talking 300 lbs. Now I have never weighed all 4 corners and doubt I ever will. I mean a very small change in weight at a corner is so small, it might be attributed to filling up with gas or emptying the tanks, to loading the refer or a cooler. Not to mention shifted weight. Heck even a person moving around. That’s a constant in RV’s. So my question, to soften the ride, can one safely reduce the psi 5-8 ? Now I will say the gap between my duals is about 1.5”. It would scare me a bit to lower this too much as I know I don’t want these to rub. I know I’ll get a ton of blasts about how unsafe all this is without weighing and breaking out an abacus. But I can tell you I will run different psi in my truck depending if I am hauling, going on a trip etc. Changing Psi 5-8 really does not seem to be a big deal based on road feel. I mean I have to imagine it changes that much on its own going from hot to cold climates, low to high elevations etc. Blast away.
Class A
  • enblethen's avatar
    enblethen
    Nomad
    Mar 05, 2014
    Weigh your rig!
    Then in your case go to Goodyear's website and get inflation chart for the G670 tires.
    That will give you a bases for your tire pressure. I run five pounds more then the chart shows.
  • Executive45's avatar
    Executive45
    Explorer III
    Mar 05, 2014
    The most common CAUSE of blowouts is under inflated tires.

    If you're looking for someone to agree with you to run your rig in an unsafe condition, you're not going to get it here, at least not from me. While you may never four corner your rig, (I know it's expensive) at least weigh it on a CAT scale and know your axle weights.

    I'm wondering though, you say, "The sticker inside says to run them at 83 psi." What sticker are your referring to? I've never seen a sticker that says to run tire pressure at an oddball number.

    The lower PSI on your tires will certainly soften the ride. Why not run them all at 20PSI..:h

    Good luck to you, if you choose to run your tires as you've described, please make sure your insurance is up to date....just sayin....Dennis
  • Effy's avatar
    Effy
    Explorer II
    Mar 05, 2014
    Executive wrote:
    The most common CAUSE of blowouts is under inflated tires.

    If you're looking for someone to agree with you to run your rig in an unsafe condition, you're not going to get it here, at least not from me. While you may never four corner your rig, (I assume you're too cheap) at least weigh it on a CAT scale and know your axle weights.

    I'm wondering though, you say, "The sticker inside says to run them at 83 psi." What sticker are your referring to? I've never seen a sticker that says to run tire pressure at an oddball number.

    The lower PSI on your tires will certainly soften the ride. Why not run them all at 20PSI..:h

    Good luck to you, if you choose to run your tires as you've described, please make sure your insurance is up to date....just sayin....Dennis


    Someone get up on the wrong side of the bed? Jeez, lighten up, it's a question. Yes my Sticker says an "oddball" number. Perhaps Thor should have consulted with you on this first, as I am certain weights and measures all come out to evenly divisible numbers. Little exaggeration and doom and gloom here huh? I am talking 3-8 psi. I am not too cheap, It's a light rig with variances of 300# per wheel between 8psi. I could get that leaning agianst it. Now go get a snickers.
  • Flanz's avatar
    Flanz
    Explorer
    Mar 05, 2014
    You may or may not like any of the answers given to you, but the real answer is to weigh your coach - all four corners and if you can weigh the whole rig and each axle. This should be done with your rig setup as if you were going on a "normal" trip. Once done, you'll have your answer. No if and's or but's about it.

    You mention this "300lbs" and a "light" coach. Well, guess what, weighing your coach will confirm this. Do yourself a favor - go weigh your coach.

    -paul
  • Effy's avatar
    Effy
    Explorer II
    Mar 05, 2014
    Flanz wrote:
    You may or may not like any of the answers given to you, but the real answer is to weigh your coach - all four corners and if you can weigh the whole rig and each axle. This should be done with your rig setup as if you were going on a "normal" trip. Once done, you'll have your answer. No if and's or but's about it.

    You mention this "300lbs" and a "light" coach. Well, guess what, weighing your coach will confirm this. Do yourself a favor - go weigh your coach.

    -paul


    Where does one weigh their coach? I assure you I can afford it. Unless of course Dennis wants to start a fund to help me out. And the 300-400# variances are on Goodyears's grid. That's the difference in weight at the wheel from 75-85 psi for my tires. I didn't make that up and weighing wouldn't have told me that. Weighing will tell me where I fall, but the weight ranges are what they are.
  • Flanz's avatar
    Flanz
    Explorer
    Mar 05, 2014
    This may help - http://www.rv-dreams.com/rv-weighing-faqs.html

    This too - http://www.rv.net/forums/index.cfm/fuseaction/thread/CFB/1/TID/217372.cfm

    Just another web site that can help - http://www.allstays.com/c/weigh-scales-locations-map.htm

    -paul
  • jorbill2or's avatar
    jorbill2or
    Explorer II
    Mar 05, 2014
    A truck stop will have a scale ...google cat scale ! As was already Named .....ask before you go on the scale they can help you figure out axle weights
  • justlou's avatar
    justlou
    Explorer
    Mar 05, 2014
    effy wrote:
    Where does one go to weigh an RV?


    These are a few places that have scales capable of weighing your rig. Truck stops, Gravel Quarry's, Farm Co-Ops. Our Co-Op will weigh my rig at not charge if I run it through off season. Most truck stops can only give you total and axle weight due to side rails on the ramps. Just axle weight is better than not knowing.
  • azrving's avatar
    azrving
    Explorer
    Mar 05, 2014
    What other things may be wrong that are giving you the bad ride? Wrong shocks etc?

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