Hey guys,

I'm looking at buying a set of pzero Nero's in size 225/40/18 which according to tirerack is available now. Our stock size is not.

I realize my speedometer will read 60 when I'm going 58.

My question is: will these make my odometer read slightly higher mileage than the stock size? If so, does anyone know by how much?

I have a lease, so I want to be able to drive my 15k per year, you know?

Besides mileage and speedometer, would this size tire positively or negatively affect any other characteristics I should be aware of? If anything, after searching, it sounds to me that this size might actually improve handling etc..

Thanks!

 

You might try 245/40/18's, as a lot of us have, it will increase your mileage approximately 100 miles per 10,000, so at 15,000 a year, it would read 15,150

 

I did a tire calculation between the stock and the 225/40's this is a warning that popped up:

Warning! When changing tire sizes, we recommend staying within 3% of the diameter of the original tire. Any more than this and you face the risk of brake failure. These two tires have a diameter difference of 3.43%

The closest I've found were the 245/40's which are close to an inch wider, but not much different in diameter.
Try this tire calculator
http://www.1010tires.com/TireSizeCalculator.asp

 

15,000 Miles on 225/40/18 would show up as 15,530 miles on the odometer. So that setup would cost you 530 miles on you lease. Got that from http://pw1.netcom.com/~sgalaba/tiresize.htm#ustires

 

Potentially a slight decrease in fuel efficiency too... you have to do more wheel revolutions to get from A to B than you did before, so engine has to do more revolutions to get you there... or so the theory goes... I've got 245/40R18s on now, no noticable decrease in efficiency.