"-rick-" wrote in message
. ..
Doug Kanter wrote:

Having hydroplaned for about 200 feet, just once, I'd agree. It's an
interesting experience. Like being mauled by a bear.

Somewhere (?) I saw a good test of the effect of tire pressure on
hydroplaning resistance. They used a plate of glass with a camera
underneath and controlled depth of water above to photograph the contact
patch as a car drove across it at various speeds and tire pressures.

The counterintuitive result was that higher tire pressure significantly
improved contact area.

-rick-

Right. And it was a combination of things with my tires. When I got to a gas
station, I checked the pressure and found it was within the recommended
range (more on this later). The next day, I called Michelin to ask "WTF?
These are two-week old tires....". They were surprised the dealer had chosen
the tires they did for my car, a 1982 Toyota Tercel. They recommended a
different one, and had their regional rep arrange for a free replacement.
But, even better, he had a long talk with me about how the car maker's
recommended pressure is a crap shoot. The numbers are often aimed at
comfort, not the best traction or handling. If I recall, the numbers were
the usual 27/29 combo. He suggested going to 32, with tires whose max cold
pressure was 40-something. That worked miracles, especially when the snow
began.

I later switched to a real mechanic, who echoed what the guy at Michelin had
said. On all subsequent cars, I've experimented with pressures above the
mfr's recommendations, and in all cases, it's resulted in better
performance. On my current vehicle, the Tacoma, I'm running at 38 lbs with
the Nokian tires, whose max is in the low 50s. This was the result of some
observations by the mechanic with regard to wear.

You really have to experiment with new tires and pay attention to what's
going on.