Hey John...
I have 245 40 ZR18's in the front of my Cobra... and 275 35 ZR18's in the rear.
I have only RARELY noticed a rub in the front and it happens when I hut a bump on a very sharp turn, say a dip while turning around in a parking lot. As far as everyday driving, never a problem. I have seen some Mustangs with your body style running 20" wheels... so something must be working.
I will give you this word of advice on having two different tire sizes. You cannot rotate them. Now this may not seem like a big deal to you but it really can be. Call it the voice of experience. I said "Awww... I don't care" Well, when the fronts start to wear a little you can feel it. When they wear a little more they begin to vibrate Ordinarily anything that vibrates can be fun if you let it but NOT on your car because it worries you to pieces hoping that it's only the tires.
Then you get stuck out in the middle of the USA in a place where you don't know a soul and have to order two front tires and let the Appalachian dog sled team put them on your car. These guys are great with sleds, but don't have a clue concerning your Mustang and what they don't break, they will shit on.
So by all means, get the same size front and back. They are not noticeably different when you look at the car anyway and will save you tons of trouble in the end.
After this set of mine wears out I'm putting the same size on both ends.245
40 ZR18 - and this time I'm going back to Nitto 555's
OH OH OH>>> Fix the date on your computer! I am so sick of seeing your post at the top of the list I could just scream. Please don't post date your posts.. it's annoying as hell and people will block you so they don't have to look at your post for weeks on end. :o)
Kate
98 Cobra Drop Top With a personal Touch... or two.
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