Tire Pressure for Rexhall Aerbus 1997XL2900
I can't find in my manuals how much the tire pressure should be in my 1997 Rexhall Aerbux XL2900 (30').I would imagine it would vary depending on how much load, but in general?? It has Mich XPSRIB L...
Forum Discussion
diplomatdon wrote:
Jeff, I would suggest you weigh the front axle, then go by the inflation recommendations on the side of the tire. You are better to run at the max rather then min as the tires will run cooler, as heat build up due to a lot of flexing is not a good thing. Remember the Ford Explorer/Firestone problems of 10+ years ago was from Ford telling the owners to run them lower to get a smoother ride. Don't believe the coach manufacturer, trust the tire manufacturer. Don
If you have weighed , why then go by the inflation recomended at the side of the tire ?? If you have weighed best is to look that weight up in list given by tire maker .
If you go by the pressure given on sidewal ( here 80 psi ) then weighing is double work.
Once you determined the weights on seperate tires by weighing , you can even add some reserve to give extra savety margin.
If you make lightest side on the axle 85% of the weight you look up the pressure for , you still wont get terrible bumping and gripp is still acceptable.
Then often heavyest side on that axle is about 95% of the loadcapacity for the pressure, and this gives some reserve for , pressure loss in time, misreadings of pressure and weight scales, etc.
This percentage can be calculated next way, Example.
Asume R side on the axle 850 KG/lbs or whatever, and left side 950 .
Then make R 85% ( 0,85) of the weight you determine the pressure for this way. 850/0,85=1000 , Left 950 then is 950/1000=0,95=95%.
Can be that the outcome then is higher then maximum load of tire ( or if dual 2 tires Dual maxload) so it would lead to higher then 80 psi AT-pressure. But this At pressure , thoug its called maxpressure mostly, is not the maximum allowed cold pressure of the tire.
Once concluded myself of an document of Semperit( Continental) that maximum cold pressure is 1.4 times the AT-pressure/maxloadpressure/reference-pressure.
Continental has Vanco Camper tires in Europe and they give on sidewall " maximum load xxxx kg/lbs AT 69 psi" and "maximum allowed cold pressure 80 psi. This is midway the 1.4 times, to be exact 80/69= 1.15 is 15 % higher.
Its also about 10 psi extra, wich for instance Goodyear allowew for ST if you want to drive 75m/h max speed ( but for 65m/h you then also are allowed to use 10 psi extra above the AT-pressure.
Its a 8PR tire wich can be compared to D-load, but European system alllows exeptions like here 69 psi instead of the standard 65 psi belonging to D-load/8 plyrated .
Michelin Agillis XC ( C for camper as we call a motorhome in Europe) has a similar idea but only gives maximum pressure apart from the notation of maximum load and dont give that 69/70 psi AT pressure on sidewall of those tires, even calls it AT 80 psi on the newer tires , wich makes the confusion only bigger.
Wrote Michelin about it because in Pressure/loadcapacity list I got from them , the XC is given the same list as the Agillis 81 , and they wrote me that its a D-load tire but the 80 psi is to cover peakloads , and I translated that to expected overload on tire for the Motorhomes that are used in Europe mostly .
Those are most GVWR 3500kg/7700lbs because normal driverslicence in Europe is for max GVWR of 3500 kg .
