Changing wheel sizes....?

[slvr08gt]

Ok, my black saleens and tires should be arriving soon and I am curious to know what differences I will feel if any from the wheel change. Currently I have 255/35/20's all around and my new setup will be 275/35/18 in the back and 255/35/18 up front. From what ive read, alot of guys that stepped up to 20's said they felt a slight loss in power because of the larger rim size. I cant really verify that because I threw on my 20's 4 days after I bought the car and never really got a good feel for the cars power in those 4 days. So, my questions is. Will I notice any difference in power at all? Is it possible that I could see a slight increase in MPG stepping down in wheel size? Thanks in advance, Nick

 

[Hawgman]

I doubt you will feel much power difference, but there should be a little if the 18s weigh less. As for MPGs, well, that is all going to depend on the difference in revs per mile between the two setups. How many revolutions per mile do your current tires make, how many will the new ones make?

 

[slvr08gt]

im not sure how many revs per mile im making right now. How do I find out? Nick

 

[rojizostang]

plug your tire size in here, it'll tell you all you want to know

http://www.discounttiredirect.com/direct/brochure/info/tmpInfoTireMath.jsp

 

[TennesseeStang]

I feel a difference when I put my stock 18's back on but not huge.

 

[slvr08gt]

plug your tire size in here, it'll tell you all you want to know

http://www.discounttiredirect.com/direct/brochure/info/tmpInfoTireMath.jsp

Thanks! Ok, my current revs per mile are 746.21 and the new wheel/tire setup will be 788.47 making a difference of 42.26 revs per mile. So will the difference in revs per mile help or hurt my MPG?? Nick

 

[rojizostang]

i suppose in theory it would hurt, but i doubt in reality you'll notice much difference. the percentage of change isn't all that much. you could possibly feel a little performance increase with the smaller tire, like changing a gear size maybe, it's only about a 5.6% change

it would be like going from a 3.55 to a 3.73 gear, which is about a 5% change...if i figured correctly

 

[slvr08gt]

Great info! Thanks again, Nick