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Old 05-23-2011, 01:31 AM   #26 (permalink)
mcrews
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Quote:
Originally Posted by Big Dave View Post
Increasing tire OD almost always backfires and MPG is reduced.

It might work if you were a long-haul trucker who can maintain the same speed hours on end, but most of us have to deal with stop-and-go situations.

Rotational moment of inertia goes up with the square of diameter. That means those four "flywheels" have to absorb more energy to increase their RPM. Until the tire RPM increases road speed doesn't increase.

Another evergreen myth that deserves a sticky.
A 'MYTH" is something that can be easily disproved.
A 'MYTH" is usually expressed as an absolute.

MYTH: Increasing tire OD almost always backfires and MPG is reduced.

meets the first test.........

It might work if you were a long-haul trucker who can maintain the same speed hours on end, but most of us have to deal with stop-and-go situations.
Meets the second test!


All by the same poster!

please refer to ALL my posts. I run larger tires. I get better mileage.

After all NOT all of use poke around town. Some of us drive 30-35k miles a yr and just achieved 30.4mpg w/epa of 22mpg.
Increased tire size accounted for 2.2mpg of the 30.4.

caveat: you need to spend some time on the freeway or at a cruise speed to gain a noticeable increase.
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ECO MODS PERFORMED:
First: ScangaugeII
http://ecomodder.com/forum/showthrea...eii-23306.html

Second: Grille Block
http://ecomodder.com/forum/showthrea...e-10912-2.html

Third: Full underbelly pan
http://ecomodder.com/forum/showthrea...q45-11402.html

Fourth: rear skirts and 30.4mpg on trip!
http://ecomodder.com/forum/showthrea...tml#post247938

Last edited by mcrews; 05-23-2011 at 01:40 AM..
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