Quote:
Originally Posted by mcrews
Welcome.
there are numorous threads on this.....did you even search?
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No I didn't. Sorry. I know... I know... first rule of fight club is...
Funny thing is, in most of those threads I read, you pop up and say the same thing you said to me. "Did you search?"
So after reading some threads on the first and second page of search results and the link CapriRacer posted...I have came to answer my questions in following manner. Correct me if I'm wrong.
1.) The larger of the two wheels of the same weights is less FE because the weight is farther from the center thus using more energy to get going. Once up to speed the difference is negligible, especially since I'm looking at wheels of the same weights.
2.) The wider tire (245) is better because it actually has less RR. My previous thinking that wider tires have more rolling resistance is wrong. It is actually the opposite. The wider tire is less aerodynamic (barely) but is more than made up with the lesser rolling resistance. The wider and taller tire is also effectively a lower gear ratio thus increasing FE. The increased weight (2-3 lbs.) of the wider tire 245 compared to the narrower 225 will use more energy when accelerating, but once up to speed the difference is again negligible.
Thanks for the help. I'm going with the 245/40/19's. Better looks and better fuel economy to boot.
According to the tire specifications. The new tire is 0.4" taller effectively making my car 0.2" taller. (Will be 57.9" tall, stock is 57.7") This is great because this also means a 0.2" reduction in wheelwell space which is good for aerodynamics and aesthetics, but is also bad because it makes my car 0.2" taller which is bad for aerodynamics and aesthetics. Since I was already planning on lowering my car (20mm) for the handling benefit, I will also benefit from a lower car (will then be 57.1", stock is 57.7") and even less wheelwell space (reduction of 1") which is both great for aerodynamics and aesthetics.
Coming from a performance oriented mindset to an ecofriendly mindset, I'm finding that there is a lot of similar shared benefits to both performance and fuel economy. This is so FULL OF WIN!