royandsharont replied on 19/12/2014 20:05
Posted on 19/12/2014 20:05
I have a Bessacarr motorhome based on a Fiat Ducato Maxi chassis with an Alco extension chassis attached. The vehicle is 7.5m long and has a maximum plated weight of 4005kg with a maximum front axle of 2100kg and the single rear axle of 2400kg. My Swift owners handbook stated I should use 5.5 bar pressure in all tyres.
Fitted as new are VancoCamper tyres, size 225/75 R 16 CP .116 R showing a max psi of 69 on the tyre wall although it does also say on the tyre wall that for camper vans the max pressure can be increased to 5.5 Bar.
After reading many comments on here and looking at the Tyre Safe Organisation web site I was still unsure of exactly what tyre pressures I should safely use. After reading a thread which indicated Continental Tyres were very helpful I decided to contact them and their reply was almost instantaneous from their Technical administrator, Ian Jackson, who sent me an excerpt from their manuals for my specific size of tyre. It showed the pressures to be used at different axle weights. I confirmed with him that the way I was reading the chart was correct and although I cannot insert the pdf document here I thought other users with the same type and size of tyre may find the information helpful. He also added that to run the tyres with a higher pressure as opposed to lower pressure would help reduce overheating of the tyres.
There is a minimum pressure of 3.00 bar which has to be applied to my front axle despite me generally never managing to get the axle weight to be more than 1640kg. The chart is for single wheel two axle vehicles, e.g. not tag axles or double wheel rear axles, all pressures are in Bars and weights in kilogrammes. One Bar is 14.405 psi.
For my normal running weights of 1640kg front and 2300kg rear I should use pressures 3.00 and 5.00 Bar respectively. I hope this helps others.
Regards, Roy
Pressure in Bars 3.00 3.25 3.50 3.75 4.00
Weight front axle single fitment 1730 1845 1960 2070 2180
Weight rear axle single fitment 1540 1640 1740 1840 1940
Pressure in Bars 4.25 4.50 4.75 5.00 5.25 5.50
Weight front axle single fitment 2285 2395 2500
Weight rear axle single fitment 2035 2130 2225 2315 2410 2500
Sorry but the chart would not appear as it had been typed in Word so if you take all pressure readings from the left and then marry them up with the weights also starting from the left you should be able to see the correct pressures. If you are unsure then please check with Continental Tyres direct on mailto:Administrator.Technical@conti.de
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royandsharont
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