Re: Hydroplaning

[Mark Pollan <Mark.POLLAN@mci.com>]

>Tire pressure determines the downward force that is exerted on the water.
>You need this force to accelerate and move the water out of the way.

>An analogy:     A water skier has to go a lot faster to ski barefoot than
>                is nessecary when using skis.  Skies spread the weight
>                (downward force) over a larger area allowing more water
>                to support him.

>To drive in the rain without hydroplaning you need a small tire contact
>patch (high pressure, high force per unit area) and low speed.

Ah waterskiing! Something I can relate to. Me thinks the confusion on
tire pressure stems from the fact the the inflation pressure is for
the most part immaterial. It is the the PSI of force exerted over/on
the contact patch area. Continuing with the above analogy, you gotta
go faster to get/keep a 300lber on top of the water than a 200lber
given the same size ski.

Mark Pollan, '86 5KCSTQ 256K Miles and 3300lbs?