LAC: Biodiesels, Diesels, TDIs' etc...

[Taka Mizutani]

Chris-
As I have been corrected several times, the contact patch is determined
by the weight of the vehicle. Putting a lower profile tire, a wider tire,
etc. on
the car only changes the shape of the contact patch.

As it applies to fuel economy, a wider lower profile tire has a contact
patch
that, when viewed head-on, is wide and short- this presents more rolling
resistance
and thus the reduction in fuel economy.

Tall narrow tires have a long, thin contact patch and thus is better for
rolling resistance.

The wide short contact patch is good for cornering but is actually worse for
braking
and acceleration in absolute terms- the tire compound, tire construction and
a million
other considerations make this a much more complicated thing than just
looking at
the contact patch.

If you're going to worry about fuel economy and assuming your car is running
in top
condition, you would have to resort to low rolling-resistance tires. A lot
of Prius owners
complained about these and thus Toyota switched to a more conventional tire
later on.
The low rolling-resistance tires don't ride well, IIRC.


Taka
riding on super sticky and stiff sidewalled tires but managing 24 mpg around
town