hydroplaning

[Mike Arman]

>"Cat ^. .^ ~" <iceisit at earthlink.net>
>Subject: Re: Tire Time - Nokians !
>
>
>I have Nokians from Finland on my 89 200 Turbo and I can tell you that by 
>far these are the very best tires I have ever driven on. I cannot get them 
>to hydroplane . . .



Oh, yes you can . . .

Hydroplane speed is 9 times the square root of the tire pressure.

If you are running 30psi, the square root of the tire pressure is 5.45, 
times 9 = 49 mph hydroplane speed.

35 psi means 5.9 times 9 = 53 mph

40 psi means 6.32 times 9 = 57 mph.

This is straight from the FAA, which does have an obvious interest in 
hydroplaning. The formula was found to be pretty much independent of tread 
pattern, tire manufacturer, etc. The problem is STANDING water - not just 
"wet pavement". Some tread patterns do help prevent the buildup of a wedge 
of water at the front of the tire (on ordinary wet pavement), but if you 
blast through half an inch (often as little as 1/8") of standing water, 
you're going sailing, like it or not.

Always remember the quattro traction formula: 4 X 0 still equals 0


Best Regards,
Mike Arman