Originally Posted by lindy
I know that my weights are different but for me as rule of thumb, when I'm towing the TT I set tire press at max on sidewall of tire knowing that I've got tires at almost max load. Then when not towing I set press at mfg recommended press as on door sticker.
This is the safest (load wise) if you actually know that you are not over the max load for the tires. However when towing with the pressure inappropriately set at MAX, (In My Opinion):
1) It will also make for a harder ride than necessary
2) Tire contact with the road will slightly be compromised as there will be a higher load across the tread on the center ribs. Over pressurization will cause center rib wear and an early tire change due to wear bars appearing in the center of the tire before the sides.
3) The tire will partial hydroplane earlier due to less tread in contact with the ground. Total hydroplane speed is 9 times the square root of the tire pressure (a formula used by accident investigators in the transportation and aviation safety agencies for years). So say the correct tire pressure was 60 PSI and you put in 80, you would have the entire tread lifted from the road at (60 PSI) when your speed hits 69 MPH. At 80 PSI that speed would be 80.5 MPH. This might seem to be an argument for the higher pressure, but since we are normally concerned about partial hydroplaning the smaller tire footprint in contact with the road becomes a factor due to less water channels available.
FYI - Car total hydroplane speed at 32 PSI is 51 MPH. Hitting a standing puddle above that speed will lift ANY tread design tire completely off the road. Tread design (like "AquaTreads") only help with partial hydroplaning by channeling water out from under the treads.
SLOW down when it is raining!
4) Stability could be affected due to skipping (hopping) on uneven roads (washboarding)
5) Less traction on drive wheels due to a less efficient transfer of torque from the drive axles to the ground.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW