i have a hybrid van , single axle with 265/75x16 AT tyres and GVM of 2600 kg.
According to the tyre lettering max. cold pressure is 80psi and maximum load 1550kg. Load on one tyre=ATM/2 (single axle)=1300kg.
My van is a single axle so according to the formula max cold pressure/max. load xl ATM/2 is ( 80/1550) x 1300 =67 psi.
According to the compliance plate pressure at ATM is 2.2 bar which is approximately 33 psi!
The formula is either quite flawed or the manufacturers are using a different approach.
No wonder many of us are perplexed, can anyone out there shed any light on this disparity, I happily trundle along with around 45 psi with somewhat less than 1300k on each wheel.
The tyre manufacturer is the authority in regard to appropriate tyre pressures.
chookhen wrote:
My van is a single axle so according to the formula max cold pressure/max. load xl ATM/2 is ( 80/1550) x 1300 =67 psi.
This is the first mistake.
It is not the ATM that determines the tyre pressure, but the ACTUAL weight carried by the tyre. You need to WEIGH the vehicle in travel mode to establish that.
Never rely on the manufacture to get the tyre specifications or the actual weight correct.
Agree as Peter states. Obviously, different tyres can be fitted during the life of a caravan.
Also, the tow hitch takes some weight too. But probably in your case, this would not account for the discrepancy with the van plate and the tyre lettering/calculation.
I have a single axle van, weight on wheels is around 2 T after I take off tow ball weight, I run my tyres cold at 64 psi and they go up a few psi as the tyres get warm, that is what I calculated it to using an online formula. I'm not concerned as the max tyre pressure is 80 psi cold.
