On Oct 6, 3:20*pm, dgk <d...@somewhere.com> wrote:
> I was going to get two new tires for my 91 Accord at Costco. They will
> only mount new tires on the rear if you only get two. Apparently a
> study tells them that the better tires should be on the rear to
> prevent fishtailing. Odd, I would think that the front would be
> better, having the steering, power, and brakes. So which is better?


New on the rear and here's why...

From Tire Rack:

http://www.tirerack.com/tires/tirete....jsp?techid=52

Intuition suggests that since the front tires wore out first and
because there is still about half of the tread remaining on the rear
tires, the new tires should be installed on the front axle. This will
provide more wet and wintry traction; and by the time the front tires
have worn out for the second time, the rear tires will be worn out,
too. However in this case, intuition isn't right...and following it
can be downright dangerous.

When tires are replaced in pairs in situations like these, the new
tires should always be installed on the rear axle and the partially
worn tires moved to the front. The reason is because new tires on the
rear axle help the driver more easily maintain control on wet roads
since deeper treaded tires are better at resisting hydroplaning.

Members of Tire Rack team had the chance to experience this phenomenon
at Michelin's Laurens Proving Grounds. Participants were allowed to
drive around a large radius, wet curve in vehicles fitted with tires
of different tread depths -- one vehicle with new tires on the rear
and half-worn tires on the front and the other with the new tires in
the front and half-worn tires on the rear.

It didn't take long for this hands-on experience to confirm that the
"proving grounds" name for the facility was correct. The ability to
sense and control predictable understeer with the new tires on the
rear and the helplessness in trying to control the surprising
oversteer with the new tires on the front was emphatically proven.

And even though our drivers had the advantage of knowing we were going
to be challenged to maintain car control, spinouts became common
during our laps in the car with the new tires on the front and the
worn tires on the rear. Michelin advises us that almost every driver
spins out at least once when participating in this demonstration!

Experiencing this phenomenon in the safe, controlled conditions of
Michelin's Laurens Proving Grounds rather than in traffic on an
Interstate ramp in a rainstorm is definitely preferred!