Higher tyre pressures?

[El Cid]

I drive a merc minibus for the council and on the wheel-arch is written number 65, back and front, I am told that this is the tyre pressures.

Yet the manufacturers plate under the seat says the fully laden tyre pressure should be 61 psi.

Since the minibus is never 'fully loaded' I am wondering why the council think the tyre pressures should be higher!!

I think my cars tyre pressure is about 34 psi; so 65 is really high; do tyre manufactures have different pressures?

[Dardandec]

Tyre pressures are determined by the manufacture of the vehicle and not the tyre manufacture, other than to determine the maximum pressure a tyre can withstand. I tend to find tyres wear a little better if there is a pound or two more pressure in them. And the difference between 61 and 65 psi is pretty negligible anyway.

 

Technically the pressures should be changed when running laden or unladen but who does that anyway.

[elgoog44]

Tyre pressures are determined by the manufacture of the vehicle and not the tyre manufacture, other than to determine the maximum pressure a tyre can withstand. I tend to find tyres wear a little better if there is a pound or two more pressure in them. And the difference between 61 and 65 psi is pretty negligible anyway.

 

Technically the pressures should be changed when running laden or unladen but who does that anyway.

 

I do as it saves fuel and make sure the car is tracking properly under weight of the occupancy, I check my pressures every time I fill up as well, plus carry a digital tyre inflator and welts kit, the state of the roads at present mean looking after and maintaining your car are more paramount than they have ever been, until such a time as when all roads are in great shape and not full of pop holes and ruts keeping a check on tyre pressures might save the car from damage as tyres lose pressure when knocked about.

[L00b]

Technically the pressures should be changed when running laden or unladen but who does that anyway.

For every long trip with a heavy load (boot full of suitcases and 'stuff'), here without fail.

 

There is a noticeable difference in the handling of the car between adjusted and non-adjusted pressure, particularly the braking distance (longer than normal with unadjusted, normal with adjusted) and the rolling behaviour in sharper bends (no wallowing with adjusted, very slight with unadjusted). That's been common to all saloon and estate cars I've owned to date (variously Volvo, Merc, Subaru).

 

To say nothing of the increased wear on the tyres if you don't adjust (for the exact same reason you find your tyres to wear better with a slight over-inflation on 'normal use' pressure: less flexing of the wall in use).

[MSYltd]

Car and van manufacturers give you specific pressure for specific wheel size and specific type of tyre.

Different tyres might have different requirements for specific vehicles.

Plus slight over inflation is better then under inflation by same value.

This might be a way to always stay on safe side - pressure usually will only go down with time.