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Old 05-30-2008, 12:54 PM   #34 (permalink)
SuperTrooper
Master EcoModder
 
Join Date: May 2008
Location: Auburn, NH
Posts: 451

Wicked Wanda - '99 VW Beetle GLS
90 day: 29.59 mpg (US)

Green Monster - '99 Ford Explorer Sport
90 day: 16.73 mpg (US)

Dad's Taxi - '99 Honda Odyssey EX
90 day: 24.23 mpg (US)
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Quote:
Originally Posted by Gregte View Post
I always thought that, on dragsters, centrifugal force acting on the spinning tire was the largest reason that the tire has a narrower contact patch while spinning than while stationary. The same would be true of passenger car tires except to a much lesser degree due to a much slower spin speed.
You are correct about the dragster tires. The latest versions deflect much less, but if you took a picture of the tire near the finish line you would see it is almost oval. The tire narrows at the top of it's rotation (furthest from the road) and then is flattened back down due to the tremendous downforce created by the rear wing.

Passenger car tires have much stiffer sidewalls and cords than racing slicks, so actual narrowing of the tires by cetrifugal force at normal speeds is negligilbe.. Only by overinflating a tire can you reduce it's contact patch.
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