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TomKat08's avatar
TomKat08
Explorer
Feb 14, 2017

RV Tires - affect on ride

Own a 2002 Fleetwood Fiesta 31'. Ford F53 chassis. Prior owner had just replaced the tires. The tires are: TOYO M143 225/70R19.5. The tag on the driver side door says inflate to 80 PSI. The sidewall on the tire says 110 PSI. I'm driving them at 90 PSI. Wondering if the tires are part of the rough ride I'm experiencing and whether the PSI is making it worse and how low on the PSI can I go and be safe and how much softer would the ride be.. or are their better softer, smoother tires available.

Since I acquired it, I've added Bilstein Shocks, a Davis tru-trac Stabilizer, stronger control arms, and a Safe T Plus Steering Stabilizer. I'm happy with the stability and tracking but the ride is rough. (especially on these ill maintained CA. highways)

As always thanks in advance for your continued advise.
Class A
  • sdianel_-acct_c's avatar
    sdianel_-acct_c
    Explorer
    Feb 15, 2017
    We had Toyo tires on our '04 Country Coach Allure. They were "ok" but did ride stiff. We now have Michelins and the ride is noticeably softer. You have to weigh the cheaper Toyos against the better ride of Michelins which are much more expensive.
  • Jim_Norman's avatar
    Jim_Norman
    Explorer
    Feb 15, 2017
    If no one else has said it...

    Weigh the rig, all four corners separately. Weigh the rig in total as well.

    Look up the tires you have on the rig on the manufacturer;s website. Get the EXACT tire, do not assume that yours is like the one listed above or below where you think yours should be, If they aren't listed, get the manufacturer's tech people on the phone. inflate the tire to the suggested PSI for the load you are placing on the tire. If the tire is rated for less than what you have weighed in at, you need to STOP and REPLACE your tires, DO NOT PASS GO! You are looking for a major hurt to your rig and potentially your physical well being.
  • 10forty2's avatar
    10forty2
    Explorer
    Feb 15, 2017
    One other quick clarification to what Effy said... set the tires to the recommended pressure according to your coach's weight when the tires are COLD. That means after it has not moved overnight and BEFORE you drive anywhere. If the tire pressure is properly set while the tire is at ambient temperature, then it will proportionally increase for the temps that you incur once you pull out and you will not exceed the maximum pressure that the tire's engineers designed. Cold pressure doesn't mean a certain temperature, but simply means the ambient temperature and when the tire hasn't been driven on. As a general rule, you never want to increase or decrease the tire psi when the tires are hot from driving on them.

    That tidbit always trips folks up.....
  • johnhicks's avatar
    johnhicks
    Explorer
    Feb 15, 2017
    Weigh your rig and set pressures to Toyo's chart plus a few psi _or_ set it to stated max psi of the tire or rim. There is no other answer and just randomly lowering pressure for a better ride is idiocy. Underinflated tires blow out. Remember the Ford Explorer blowouts and rollovers?

    I use Toyo 8R19.5 tires and weigh 20,000lbs. By Toyo's (and others) chart I need to run 105 psi on the front and 110 psi on the rear. Oddly, stickers on the rig indicate 95 psi, which is underinflated for the stated max weight of the rig. It's not a smooth ride but it's a safe ride.
  • Effy's avatar
    Effy
    Explorer II
    Feb 15, 2017
    Weigh it and set it to the tire manufacturers instructions. The sticker in the MH is a "guide" that is required to be there when the MH leaves the factory and it's based on dry weight. The max pressure on the tires is exactly that, the maximum rated psi for that tire under max load. The only way to set your tires PSI correctly is to weigh your MH like it's ready for travel (food, people, fuel, water, clothes) and adjust PSI based on the tire manufacturers chart. There is no other answer.
  • crasster's avatar
    crasster
    Explorer II
    Feb 15, 2017
    On the bounder we just use even pressure and not go so specific on weight per corner. May be our own mistake but things usually seem pretty even. The 80PSI is the mfg weight for the ride they want you to have and not what the tire can handle. It will be rougher with more psi even though the tire can handle it. But you will get slightly better mpg with more psi.
  • racer99's avatar
    racer99
    Explorer
    Feb 15, 2017
    We run Firestone 560 on 19.5 rims and run 85 psi on all four corners,maybe a little rough on ride side but tire temps stay almost the same on all four tires-I shoot tire temps at the rest area and not concerned with temps as much as all tires being equal, has worked for us, tires are 5 yrs old and look good and no cracks-We use tire covers when parked-Rich
    pauperpride.blogspot.com
  • Tom_Barb's avatar
    Tom_Barb
    Explorer
    Feb 15, 2017
    When we bought our coach in 2009 it had truck tires on it and running at maximum pressure of rim. it did ride hard, I lowered the pressure to the advised 95-100 PSI. really didn't make much difference.

    After we saw side wall checking we changed to Michelins coach tires the change in ride was amassing.
  • Artum_Snowbird's avatar
    Artum_Snowbird
    Explorer
    Feb 15, 2017
    Usually rigs of that size use 16 inch wheels. Often 31 foot rigs do not have enough cargo carrying capacity for their frame size. The weak link is usually wheels and tires.

    I had to do the same with my truck, went to 19.5's to get the carrying capacity to do the job safely.

    Some of the max 120 psi tires can be inflated to only 75 pounds, and it does make a difference.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Feb 14, 2017
    Did the previous owner replace the wheels too? They have a pressure rating that may be a bad idea to exceed.

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