Gluemaker

iTrader: (12)

A friend of mine has some used chrome 18x9.5 c6's on his car. The rims came with 255/50/18's. it looks very odd with that much sidewall. From behind it looks like a pair of pozza cutters. He asked me what size tires to run, and I had no real answer. He is wanting to do a 285 out back and maybe keep the 255 in the front but with a smaller sidewall. What should he run all the way around?

SparkyJJO

iTrader: (11)

255/40/18 would be a more normal tire height but that is a fairly narrow tire for that width of wheel. I'd do 275/35/18 front and rear so you can rotate the tires,get the proper width tire on those wheels, and the proper tire height so it doesn't look weird and the speedometer will be correct.

02TransAm/Batmobile

iTrader: (32)

Personally, I would do a 275/40R18. If you do a search under my screen name, you'll find my thread on that size for pics.

SparkyJJO

iTrader: (11)

If you do that your speedometer will read about 4% slow (you'd actually be doing about 73mph when the speedo reads 70mph). Just FYI.

1981TA

iTrader: (7)

BTW, an easy way to check speedo differences is to use a GPS or Smart phone to verify your speed. This is how I zeroed in the speedo on my car. Blackberries, iPhones and Androids should all have some sort of pre-canned mapping app on them that shows current speed.

Ballzee

iTrader: (5)

275/35 or 285/35..

thailam5

I have 275/35-18 on mine. Heres a pic if this helps.
https://lh5.googleusercontent.com/-O...6/IMG_1282.JPG

2GOOD4U

iTrader: (1)

Man, I haven't seen a 255/50/18 on an Fbody - that's got to be a huge sidewall.

I've ran 285/35/18 on all 4 for a long time - it will look MUCH better than the 255/50.

mikep

285 35 18 tires run small today.