tyre pressures for non-standard tyres

Correct tyre pressures are always a compromise.

Correct for wear means: inside and outside edges wearing faster - increase pressure, middle wearing faster? decrease pressure. harsh ride? decrease pressure

Adjusted for the following:

soggy ride? with little feel or feedback increase pressure vague sloppy feel under heavy cornering? increase pressure no grip in wet muddy or loose surfaces or snowy conditions? decrease pressure want more mpg? increase pressure.

Correct pressure is your best compromise on the above. There can be no universal correct pressure.

Start with the stock pressure then drive it a bit, move up a couple of PSi if it feels better try a couple more if worse a couple less.

So you get a feel for "how" it feels when pressure is much to low/high start by going for a short drive with them say 10 below book, and then 10 over stock pressure. Once you see how it effects feel and harshness its easy to notice if they are too hard or too soft. You will be able to tell if its only 3 or 4 psi wrong quite easily.

Settle for what feels the best while keeping the same differential between front and rear as the book says. Then keep an aye on wear patterns as mentioned in my other post! If your best pressure starts causing wear on the outside edges increase and if in the middle decrease a bit.

Last time I checked my tyres, the front were at 30psi - a full 10psi over what they should be heh. Changing it to 20psi made the car feel sooooo much better.

Aye, but that's what it should be.

It is just holding up the front suspension though. Small fwd hatches have it as love as 24 and 26 and support an engine.

even my MR2 Turbo was set at 2bar and 2bar and a bit on the back which is over 30psi me thinks, my bm is the same but then both are close in weight, BM is 200kg's heavier i think.

It's always amazed me that the front pressures on my van (LPG Sprinter) are only 41psi - normally on a 3.5T derv van they're around 65psi all round - this is still 65 on the back but only 41 on the front. Surprised me that the difference in weight between the diesel and petrol engines made that much difference.

The key thing here is that the Clio is also likely to have fat f*ck off tyres. Skinny tyres on my road bike = 100PSI, much below 60 and you start rolling around. Mountain bike tyres run from 50psi down to about 25-30...

...it's the mid-engine RWD thingie? Little weight over the front wheels?

Justin.

Well, there's the battery :)

Damn heavy things those... I was a little shocked to see my beemer had the battery in the boot! 50:50 balance...

Justin.

those rears are wide! but why different profile?

i have 205/45/17 at front and 225/45/17 on the rear on the BM

mine too and they do mean 50:50 too, i jumped a bridge in mine and tested it lol not on purpose mind and it did shit me up!

Maybe so they are mostly just wider with the same ish sized sidewall? Otherwise it would look like a dragster.

Yea, I assume it's to stop it from looking like it has mismatched tyres.

So the body/suspension doesn't scrub the f*ck out of the tyres? (c;