6+6 Stang

hey here's deal, it's been so long since I had the car, so it was more trying to pull from my memoryu\, no matter which way goes I'm telling you your actual miles are going to be different, my experience was this, because of the profile all I can tell you for fact is that I was putting more miles on the car than I actually was driving, thus running my warranty out earlier....here put these numbers in, stock and the new size.......notice how the 20's are actually shorter than 19's in dia. and the indication you are going faster than you really are going thus putting more miles on car than you really are..actually you just need the rear cause that is the one causing the car to show 61.6 when I was only going 60, so trust me after driving 35,000 miles and you go over your 36,000 mile warranty and something happens...good luck explaining oh wait I really only have 33,000 cause tire size......I'm just trying to help not argue or prove a point, even my SCT Handheld could not tweak, my dyno guy had to finally adjust, then matched the GPS..PLUS just telling you from a 19" wheel, you will maybe be less miles or right on, but 19 NO...YOU WILL BE FASTER!!!!
orig. 245/45/19

rears 295/30/20
front 255/35/20



Now I have no idea your stock size is, but the calc. says for a 2011 mustang this is the size,

Stock Tire - 215/65R17 and if you did 295/30/20 on rear as I did....it says...not me when going 60 it says on speedo 62.3 mph , so if that is case you would be putting more miles on car than actually on it.

DarkhelmetRT

according to the calc I use, it comes out reading slower because the diameter is smaller. try this one http://www.rimsntires.com/specs.jsp

6+6 Stang

You are using one, I am using 1010's calc. 1010 sayd faster, the one you used says slower....All I can tell you is my speedo read faster than I was going so thus before i had calibrated never got pulled over...these two calulators are not matched, but I can tell you the one from 1010 using my setup will say speedo faster and it was in my car, the one you are using says I will be slower and that was not so on mine, sorry. all i found in that stock 17 " wheel was 215/65/17 not sure what 17 he has, but that is fords specs?

Hey Dark...side Note On your Calculator, type the tire size you bought on Left and the Tire you used to have on the Right...now matches???

tat2dphreak

so are very sexy Rims!! looks great!