Quote:
Originally Posted by car62
Very misleading statement. Metal weighs more than rubber. See Car and Driver Magazine May 2010, page 34, for a detailed test and explanation of the negative effects of increasing wheel sizes.
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Nothing misleading about anything I wrote. You just don't know how to interpret it. Same brand, same width, same rolling diameter tire usually weighs less in 19" than 18". Compare the PS2, Goodyear F1 Asymmetric, PZero, Ventus V12 or Contisportcontact3 weights in 245/40/18 and 245/35/19 (tirerack or manufacturer's specs) and you'll see. This is true for most tires, but not for every tire; some are about the same.
Also, a tire is not merely made of rubber. And, a high quality forged Al barrel is rather thin (<3mm) and lightweight for instance. See detailed discussion and first order approximations on total wheel weight and rotational inertia here:
http://www.m3post.com/forums/showthr...weight+inertia From an acceleration point of view, it is more or less a wash.
From a merely weight perspective, the difference in the 18" and 19" tire weights is often ~1lb. The difference between the same model similar strength similar offset forged 18" and 19" rims is also about 1lb (RAC RG63 is a good example, and BBS RGR might be another one). Even when there is less difference in tire weighs, the whole thing is still not a big deal as long as you chose the right rims.
Anyway, the point is, as I said earlier, if you want the "whole story" on wheel size and acceleration, you need to consider these kind of details. I don't need to read a car magazine to think through any of this.
And, as pointed out above by another person, "metal weighs more than rubber" is a meaningless statement.