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Old 03-01-2010, 11:13 AM   #1 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
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Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

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

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
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OEM tires more efficient than same aftermarket replacement

I know this has come up before, but just wanted to add this to the forum for posterity:

On new cars...
Quote:
...apart from California, [low rolling resistance] tires aren't required in North America, although they're used voluntarily to help achieve fuel-efficiency standards.

That means original-equipment tires tend to have thinner sidewalls and shallwoer treads than replacements.
From Canada, Europe develop tire ratings to reflect fuel efficiency

Also of note, repeating what has been said elsewhere on the forum:

Quote:
To put things in perspective, on average, new conventional tires have 20 per cent more rolling resistance than worn ones. So when you replace your tires, your fuel economy drops by as much as four per cent.


It's not yet clear whether the same applies to low-rolling-resistance tires. But, in general, they at least start with better efficiency.

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has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
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