Announcement

Collapse
No announcement yet.

Do you ReAlLy adjust tire pressure on rig and TV based on measured load? Really??

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Do you ReAlLy adjust tire pressure on rig and TV based on measured load? Really??

    Ok, I have gone through all 8 pages of search results for "tire pressure" and don't see a consensus of opinion.

    Seems that most folks air up to max pressure on tire sidewall. Some say just put all at 120 and call it a day. Even though we know left side is typically heavier than right side I did not find that accounted for. I also didn't find any real focus on TV tire pressure.

    So what do you veterans of the road recommend as best practice for the newbie

    Thanks so much.
    Michael and Katherine (Moe and Flo on the go)
    Full-time since March 2017

    2016 F450, DRW, Crew Cab, Goodyear airbags, TrailerSaver TSLB2H hitch
    2014.5 Elite Suites 38RESB3, vanity slide, customized. #6987

  • #2
    TV 80 front all the time, rear duals 45 solo and 60 loaded.

    RV 110# more than enough with the GY H tires max pressure of 120#. Weigh your rigs and adjust per tire pressure guide.
    39TKSB3 "Highly Elited"

    2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's 37,500# GCVWR "Towing Beast" "HeavyWeight" B&W RVK3600

    Comment


    • #3
      There are as many opinions on tire pressure as tow vehicles and brand of rv. If you research what the RV and tire manufacture's recommend you will find they will ALL recommend pressure set according the the load.

      Every tire manufacture has a chart and it will give the recommended pressure per load. If you do not find a chart then they use the standard wheel and tire association charts. The GY charts are off the standard charts. Michelin is always a bit different. They also show the load on DRW for both tires instead for each.

      If you do not know the real weight by weighing each wheel then run the recommended side wall pressure until you do. Then once you have the info, adjust to the recommended pressure. The pressure on the chart is a Minimum rates pressure for the load. From there it s best to bump it a section o the chart to allow for additional weight down the road. Say around 100-200 more lbs load. Using that, you wold be covered in most any circumstance.

      Do use the heaviest tire on each axle on the truck and the heaviest tire on the whole trailer to calculate the min press. So, if one tire on the trailer is 3800lbs then all tires on the trailer are treated as 3800lbs. Same goes for each truck axle. Except each truck axle can be treated independent.

      Dual rear tires on the trucks likely will not be loaded very high individually, that means the charts may show a pretty low recommended press or the absolute min. That is were you will have to apply some good judgement. Running below 60 would not be advised and also no real need to run them at 80 either. Just will give a harder ride. If towing with a pickup, front tires will perform best at max sidewall pressure. Steering stability and road feel will be improved when towing. When solo, run what manf recommends.

      An example for the trailer....our 38RL3 MS heaviest tire calls for 100psi on the charts. I run them all at 105psi cold. This is for the 17.5" GY 114 H rated.

      It is best to not go by what anyone else runs, weigh the trailer on each wheel and use the charts. Or run max sidewall until you do.

      Bill
      Bill and Joan
      4 Collie pups
      01 Volvo 770
      05 38RL3 #2046
      05 Smart Passion loaded piggyback

      Comment


      • #4
        Bill's answer is right on. Weigh your tire contacts individually and then set the tire pressure according to the tire manufacturer. Here's an exercise for you, these are my weights according to the "Weigh - it" team.:

        Door side front: 3900 lbs. Door side rear: 3525
        Offdoorside frnt: 4425 Off dr side rear: 4175

        I use Michelins, 17.5" and from the chart for the weight, the chart says at 120 lbs. the max weight is: 4805 lbs. The table shows that for each tire here is the pressure (the chart show weight for a single axle so multiple the weight by 2 to find pressure) :

        DSF: 95 PSI DSR: 85 psi.
        ODSF: 110 psi ODSR: 105 psi

        So I run all my trailer tires at 110 PSI for simplicity, but could run the at different pressures as shown. I do the same thing for my truck tires. I don't think most owners have ever done this exercise, but Stacy Frank (Weight-it) suggested doing this and knowing your tires are right.
        John & Bonnie Mc Clun
        2008 F-450 King Ranch Dually
        2011 MS TKSB3 #5793
        http://drv-owners-manual.com

        Comment


        • #5
          If I may, let me give you a "result" as something to consider. Background: We run Michelin XTAs. They're J rated. Certified speed rated as about 62 mph (though we've been know to have our moments towing above 70 as we maneuver around traffic). Per the Michelin XTA pressure-load chart, we can get away with about 85 lbs on our heaviest loaded tire (last weighted at the Escapees Rally in Gillette, WY in September 2011). (...and we need to be weighted, again, as things change.) We try to stay between 115-120 lbs in all tires.

          Our lightest loaded tire (back in 2012) is the door-side rear tire. That tire developed a slow leak (eventually found to be at the valve stem). We traveled about a year and a half like that. I'd air it up. Over a few weeks it'd drop 10 lbs, and I'd air it up again. As time passed that became more often. Sometimes, it'd get down to 105 lbs before I got to it. (Doran set to alarm at 100 lbs.) We got it fixed, and after a few more months, had the tires rotated and balanced. That leaking tire was significantly more worn than the other three when we rotated. So in our case, letting that one tire drop below 115 lbs on a regular basis really affected the wear on that tire.

          The other point I'd mention is that I've considered lowering the rig's tire pressures to achieve a better ride for the trailer. It works for tow vehicles, so why not, right? In our experience, I'd now be a proponent that it's the air pressure of the Trail Air bags over reduced tire pressure that gives our rig a better ride. We haven't been parked truly level while towing for quite some time, but running our bags about 50 to 55 psi seems to keep the airbags looking fine (generally parallel ends). Anything over 60 psi seems to shake us a little more (more stuff had moved around when we opened the trailer) and pushes the bag ends out a little at the top (if we can park at a spot sorta level).

          So that's what we've seen & experienced. Be aware as your experience will probably vary, but hopefully it gives you another point of reference to consider. Have fun! David
          David & Donna Driver |2017 F350 | 2011 MS 36RSSB3 w/Vanity Slide (#5642)
          sigpic

          Comment


          • #6
            GY tech support said to use the charts based on your heaviest tire then add 5psi. This has worked well for me.
            39TKSB3 "Highly Elited"

            2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's 37,500# GCVWR "Towing Beast" "HeavyWeight" B&W RVK3600

            Comment


            • #7
              Load chart and know the weight of the trailer axle. Next big thing is to be sure you only adjust when cold. I use a tire monitor and will go from 105 cold to 125 on a long pull. If you adjust hot will be way under inflated. Buy a good quality digital gauge.
              2008 32 TK3 Mobile Suite #4311
              2011 Chevrolet 3500HD LTZ Duramax DRW
              Trailer Saver TS3
              Tire Monitor

              Comment


              • #8
                Thanks for all the great advice. I'll be sure to have inflation guides and check/adjust as needed. Probably err on high side till we have loaded up with all of our stuff and then see if it makes an improvement in ride to drop it down. We have so much to learn.

                Thanks again!
                Michael and Katherine (Moe and Flo on the go)
                Full-time since March 2017

                2016 F450, DRW, Crew Cab, Goodyear airbags, TrailerSaver TSLB2H hitch
                2014.5 Elite Suites 38RESB3, vanity slide, customized. #6987

                Comment


                • #9
                  get you trailer weighed by trey susan at a rally they write every thing down, my was harder for them because of the size of the semi truck tires, but they got the info and mailed me my paper work still have it in the front closet. i an sure the trailer is a lighter than when weighed 5 yrs ago, got ride of some things we don't use on the road

                  Comment

                  Working...
                  X