Blue Meanie

I run 255/45/18 on my fanblades. They are the same overall height as 235/50/18's.

rojizostang

not sure who you're asking

i've got 245/45/18's up front
275/40/18's in the back

waykooljr

I would go with 255/45/18, this will give you good balance between ride quality and handling.

The 275/40/18's rim width range is 9-11 inches.

rojizostang

thisi combo will have the front tires a little taller than the rear. the 245/45 and 275/40 combo has the tires almost identical in diameter

157dB

255/45-18s
Almost the same revs per mile as the stock 18s.
No speedo error or the need to use a tuner to fix it.

Z06 Killer

Stock tire of 235/50/18 is 27.3" overal
255/45/18 is 27" orveral this means your speedo is 0.8% too fast. When is says 60 you are going 59.5
275/40/18 is 26.7" and is 2.2% too fast. this will read 60MPH when you are at 58.7MPH
275/45/18 is 27.7" and is 1.8% too slow. At 60 on the speedo you will be traveling 61.1 MPH

the 255's are a great size for the rears if you are N/A but if you are F/I or go to the strip alot then I would advise either of the 275 options I gave you. They will fit and will be just fine it is just barely outside what is considered standard. Ford put some damned skinnes on the 8.5's for some reason

MELLOWYELLOW06

265, MAX 275

Leoleo

Here is a tire calculator site. Put in your stock and other tire sizes. Gives you information a wheel width range, speedo diffs, other good stuff. The stock 18inch fan blades are 8.5 inches in width. Also if you ever need to buy a replacement fan blade wheel. Buy it from Ford Racing and not a Ford dealer. Ford racing sells them at $210, while a Ford dealer sells them at about $450. Just FYI.

http://www.1010tires.com/TireSizeCalculator.asp