As it actually allows the tyre to 'cut through' the surface layer of surface water and make contact with the road.

By adding pressure, the face of the tyre 'balloons' out at the centre, which allows the profile of the the to work better in the wet, and stop aquaplaning.

The reverse is also true, under inflation makes the tyre face go shallow, resulting in less contact patch with the road, but in the wet it has a negative effect in that the tread pattern doesn't pump the water out because of lack of contact and the tyre actually 'rolls off' at the edges under cornering.

See here:


So, in effect, its actually better to over inflate than under inflate as the tyre can still do work as intended and the more air allows the tyre to run cooler as well.

Cheers,
Tricky

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"Not Speeding Officer..........Qualifying"

Simon, i'd say the 50 psi of pressure is the key, with the tyre being so hard there's very lillte sidewall movement in the tyre for shifting weight. Plus the wet conditions, plus you never know if theres been a recent accident in that spot & could have been oil on the road.

I've fiddled with tyre pressures in motorkhana's for years, i tried 50 psi once & the rear slide was un controllable, i was losing time everywhere. I now run mine at 40 psi & the control is great

I know your a sensible driver & all (except at Jugiong in the bomadore)

Doogie

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I won Hay once, here's the pic to prove it..


Hay, it's not about the car, it's not about the venue, it's about the people that come here. Peter Dwyer, Mayor of Hay NSW.