Tyre pressures

[syncropaddy]

Is there a difinitive answer somewhere on this forum on tyre pressures?

[jebiga41]

think theres stuff on the brickyard bentley says about 40 psi I think

[Aidan]

there's a definative for standard tyres, there's a method for calculating for other tyres that have got the load figures stamped on them, ie max pressure 65psi at 850kg sort of thing, you take half the axle rating and ratio the psi against the load, so front axle iirc 1300kg, so 650 is half, 650/850 x 65 = 49psi, I found if you worked this out on a standard tyre you got pretty much the same figure as in the handbook and use this as a guide to working out pressure for 15" tyres and then trial and experience do they drive nice, fuel economy ok, wear even, ended up 3 bar rear 2.5bar front (which is the same as 205R14Cs)for ColwayMTs (they are a retread remember )and they've been fine at that, air down to 25psi when required for grip/footprint got 4 years out of them and there's still a bit of life left for the project in them.

[HarryMann]

That's Wik'd now https://club8090.co.uk/wiki/Ge ... ssure_calc

and then there's this:

http://www.tirerack.com/tires/tiretech/tiretech.jsp

[syncropaddy]

Aidan, looks like you've been Wikied ....... you need to watch that Harryman fella

Well using that formula I should be running 225/70/15 tyres at 36 front and 38 rear. Currently I am running 29 front and 36 rear based on the assumption that the front should be roughly 80% of the rear, which if you look at page 123 of the owners handbook where all the tyre pressure values are, you will see that thats how it calculates out. the 205r 16 run at 25 front, 30 rear.

I choose 36 for the rear cuz its half way between the 205r/14 and 205r/16 values cuz 15" is between 14" and 16". Im trying to soften it all up a bit cuz the van bounces about a good bit.

[Andy syncro-nutz]

Paddy! Put some bloody furniture in it