I need to buy tires like yesterday, and I've decided on Kumho Ecsta SPT's per everyone's recommendations. One thing I'm a little confused about is which size to get. A lot of people are getting 245/40/18 rather than the recommended 45. Is there an advantage to this? Any disadvantages?

 

45 series is for the stock 225 width. If you want the 245 width (which will fit on the OEM 8 inch wide rims), 40 series is what you want.

 

The 40 series is closer to OEM circumferance, and will effect the speedometer only a bit.

The 45 series are bigger around...more error

 

oops i meant 225/40/18 and 225/45/18. Is there any way to adjust the speedometer?

 

Wait, would it be a mistake to order 225/40/18? Should I just go for the 225/45/18 instead?

 

go with 245 / 40 / 18. Very little change to your odometer (bout .5 mph) I believe. It would be quite difficult to adjust your speedo.

 

thanks for your help man. I'm clueless when it comes to tires.

 

no problem, so was I until recently.

 

*very* quick overview on how to read tire dimension #'s:

let's use 245/40/18 as example

245 - 245mm of tire TREAD WIDTH
40 - thickness of the SIDEWALL as a percentage to the tread width (in this case the sidewall is 40% of 245mm)
18 - fits 18" wheels

 

Thanks guys. I ended up getting 245/40/18's. The 225/40's would have been like a 5% change in speedo and odometer, and I def wanted to switch to a 40.

 

The sidewalls on the 245/40 are almost exactly the same as the 225/45...so they will look the same in profile...but the extra 3/4 inch width will be nice...both for looks..and traction