Re: Wet weather tire pressure

Bruce Graham

In article <5som70d95bilkmuln0cntqo5cbttgbt2ld@4ax.com>,
usenet@mousepotato.com says...
> On Mon, 12 Apr 2004 14:10:06 GMT, Harris
> <aharris@bookworm.suffolk.lib.ny.us> wrote:
>
> >DRS <drs@removethis.ihug.com.au> wrote:
> >> Curtis <curtisr@kingston.net> wrote in message
> >> e7b5232.0404120449.79fc0f31@posting.google.com
> >> > O.K., I hate to be so stupid but is there any evidence to suggest that
> >> > a lower tire pressure will help traction in the rain?
> >
> >> No.
> >
> >I say yes as it puts more rubber in contact with the road (larger contact
> >patch).
>
> "airing down" is a common practice in the 4WD field, in order to
> spread the tread out over a wider area to improve the contact patch.
> Hummer offers an option called CTIS (Central Tire Inflation System)
> which allows the diver to alter the tire pressure in front/rear pairs.
>
> Try it and see.
>
> Michael J. Klein

yes and no...

low pressure on 4WD 14-20 psi is for sand, 18-28 psi is for rocks
not wet bitumen.

The low pressure limit is usually when dirt gets under the bead causing
a leak, or it rolls off the rim when turning or spins on the rim when
braking/accelerating.

Big tires can go lower pressure and beadlocks allow lower pressure again
for competition.

On rocks, lower pressure allows the tire to mould around sharp edges
better and reduces cutting, chipping and punctures.

That hummer CTIS is nice though! You see similar systems on off-road
racers. eg. Paris-Dakar