On Jul 7, 2004, at 21:59, Terrible Tom wrote:
> Larger diameter tires will make fewer rotations than a smaller tire.
> Thus your drive line and engine will make fewer revolutions as well...
> thus in theory, giving you better fuel economy.
Only to a point. if you drag your RPMs too low, you eat all the gains
becuase the engine is working harder to maintain, say, 1800 versus
making a very easy 2200. Larger tires and wheels are also more
rotating mass that takes effort to spin up, keep spinning and spin
down.
I went with 265/70-17s on my v8 CC, and saw milage drop a hair, coming
from 30" tires (actual measurements were a 29" to a 31.5" diameter,
same tread)
> Critics of this thinking say the "taller" ride the tires give makes
> the truck less aerodynamic and defeats the possible fuel economy
> gains.
ride height doesn't change enough when you're talking a 1-2" difference
in diameter. that's 1/2 - 1" in ride height, but a 10% difference in
final drive speed (from 30" to 32").
-- Michael Maskalans <http://mike.tepidcola.com/dak/> '98 Dakota CC 4x4 318 '84 RamCharger 4x4 360 mobile.612.618.4652 campus.585.274.2246 fax.954.697.0487
This archive was generated by hypermail 2b29 : Sun Aug 01 2004 - 00:46:14 EDT