I'm looking to buy the 18x9 Shelby Torq Thrust wheels (all around). I'm also upgrading the front brakes to GT brakes (brackets + rotors only) to get some better stopping power and make sure I don't have clearance problems. My question is what tire size do I need so I don't have to adjust the speedometer? I plan on using same tire size for all 4 wheels and I currently have 16" stock wheels and tires.


P.S. sorry I know this has been answered before but I couldn't find the thread

 

anybody?

 

im not 100% shure but if you have an X cal or Diablosport tuner type thing, it should reconfigure your gagues. As for tire size...check the site your getting them from and look for an add Tires option.

 

I dont have a tuner so thats why I want to get tires that won't require spedo calibration but I'm unsure of the size

 

If you have the stock 16" wheels with 215/65/16 tires, then your overall tire height is 27". Your new 18" tires would obviously need to be that size also-- to avoid recalibrating the speedometer. It can be done with an SCT tuner though.

You could go 255/45/18-- equals the exact stock size of 27".

245/45/18-- 26.7"
245/50/18-- 27.6"

If you want wider tires on the back:

275/40/18= 26.7"
275/45/18= 27.7"

My rear tires are 295/45/18, or 28.5"-- and my speedometer was off by 5 mph at 60. It's now corrected with my tuner.

 

thank you thats exactly what I needed to know