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Old 01-19-2010, 05:24 PM   #20 (permalink)
wyatt
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Quote:
Originally Posted by PaleMelanesian View Post
The Firestone FR380's are not a great tire. That was my previous set. I don't know about mpg, as that was before I was tracking the numbers. They wore down pretty quickly - I can't remember, but 40k miles or so. They also had poor traction, especially on wet roads. I'm not talking about hydroplaning, just a wet road surface. Very easy to spin the tires on a start, or to skid sideways on a turn.

My new Michelin Destiny's are in another class altogether. Too bad they don't come in your desired size. (175/70/13 is what I have)
These are the tires that I am running now. The 40,000 miles you quote is what they are rated at, so no surprise there. They are a 35psi tire, which hurts my FE a bit from the last tires that I had. I did some coast down testing last year and the Cd,Crr for my car came out to 0.28,0.012 at sidewall max pressure (before starting), and with tires warmed... I don't know what qualifies tires as LRR, but I think some tires get down to the 0.009 range.

I tried to get some 80,000 mile Michelin's, but they were only available at CostCo (and I don't have a membership). They were 44psi max, so I figured the extra pressure would offset the wider tire. They were almost exactly twice the cost of the Firestones, so the dollars per mile calculation was about the same for both.

EDIT:
Oh, and I think Basjoos has said that he sees increased FE with wider tires. He speculates that the reason is because he does such a good job deflecting airflow from in front of the tires. When you think about it, it makes some sence... for the same tire pressure, there will be the same amount of AREA in contact with the ground... this means that the thinner tire will have to flex more since it's contact patch is longer, where the wider tire flexes less.
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Last edited by wyatt; 01-19-2010 at 05:30 PM..
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