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Old 12-16-2007, 12:39 PM   #9 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,451

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 55.97 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 67.41 mpg (US)
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I haven't looked at tire specs, but what you say seems reasonable.

It also makes sense that wheel/tire mass makes little difference at constant speed.

But I'd still get the lighter wheels if I could. The majority of my fuel savings comes from the P&G technique = repeatedly accelerating (and at a fairly brisk rate). In those circumstances, or for driving that's primarily urban, it makes sense to reduce wheel/tire mass. For highway cruising or DWL, not so much.

About the question of RR being solely a mass issue, I wonder how much aerodynamic lift a typical car generates at highway speeds... (Just kidding.)
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