I have the stock rims on my 01 cobra with some pos tires that were on the car when i got them. Iv noticed its about time to change my tires, however the KDW2's dont have a 245/45/17 and i searched through the search thread and saw that a few people asked this question before and members replied saying that a 275 is the biggest you could put on without any problems. Now the problem starts...I mentioned to my dad that there were no 245/45's and that i want to put on 255/40's but he says that once you change tire size from factory you run into problems. Any info on anyone experiencing problems changing such a minimal tire size?

Thanks

 

Your daddy is talking out of his a$$, IMO.. I did 275 40 17's with no problem...

 

I am with mfj here (but would say it a little differently )

The only issue that will come into play with larger/wider tires or wheels, is rubbing or speedometer inaccuracy. You will not have any rubbing running a 275 at any corner of a SN95+ Stang. The speedometer is easy to fix and will not come into play at all if you keep the same overall tire diameter than stock.

 

Hey Guy check this link out http://www.ezinearticles.com/?How-Ch...rous&id=339802


Anyway yes you can change the tire size, bigger, wider taller or all of them. But when you do change you will have premature tire wear,possiblely hitting the frame and or bumpers. This increases more when you lower the vehicle. Now add in the alignment specs which are for the tires size('s) listed on the drivers door and you get uneven wear. Ford just like GM and Chrysler and all the other have engineers who spend hunderds of hours putting together the right tire for the suspension.

thoese who want to make the change go for it if you have the bucks. Me personally I will keep my vehicle within specs for a street car / daily driver. A track car well that is a different ballgame.

Good luck and by the way in case you could not tell i am dad.

 

Yeah I'm running 18x9 w/ 245/45/18’s up front and 18x10 w/ 285/35/18’s in the rear and I haven't experienced any mechanical problems or abnormalities so far ::knock on wood:: lol --not that I'm expecting any

 

I have an 01 cobra with h & r sportlines on it and the stock rims. I have 275 40 17's on there with no problems at all. My speedo is only one mph off and i have no rubbing issues at all. so yeah you can go with that size tire with no problems. and i have not had any abnormal wear problems.. my tires is wearing out just like stock..

 

Changing tire size will NOT lead to premature wear or rubbing if you do it right. The biggest factor is keeping the correct over all diameter. From there, just make sure the width isn't wide enough to rub at any point in the suspension travel. Also, getting an alignment is not needed unless you mess with suspension geometry.

As an example: The stock 2000 V6 (my car) came with a 205/65-15 wheel/tire combination. Roush put on 17x8 wheels with 245/45-17 tires and a 1.5" drop. With a front end alignment (mostly to add camber to offset the lowering) was done and the car was good to go. I swapped on larger Roush wheelss: 265/35-18 fronts and 295/35-18 rears on 18x9/18x10 wheels. Didn't do an alignment and was fine.