Will larger or wider wheels fit?

I'd like to have larger wheels and tires (increasing the outer wheel diameter to reduce that excess wheel well space) and/or wider tires for more grip. Then I can retire my 15's for winter tires and not worry about mounting and remounting rubber to suit the roads.

BTW, this is for my '86 fastback

How much can I increase the overall outer wheel diameter without having the front wheels rub the inner wheel wells when turning? I can't see going over 3-4" larger. Anything more would be ridiculous - any little pebbles in the tire tread would rub :biggrin:

Does anyone know how much wider I can go stock or with certain larger diameters?

Also, how difficult is it to then correct the speedometer and odometer? Isn't it just a matter of swapping a color-coded gear?

Has anyone done any of these things? Thank you for any input!

-JP

i would like to know as well, as i have the same car. would 17s fit??

I have no answers yet, but if you just want to size up your wheels' diameter and get lower profile tires (keeping the same outer wheel diameter / "rollout") then check this out:

http://www.venommotorsports.com/library/tirewheelcalculator.asp

For those who don't want to mess with the calculator, you should be able to go from 205/60r-15 to 215/45-17 tires on 17 inch wheels with zero changes to the speedometer gearing. Also 215/40-18's, 205/35-19's, or 205/30-20's should fit with virtually no error.

i've read that we cant go much wider than stock due to the control arms/coil spring/strut towers. not sure tho.

i have 225/70r-14 on my 85 gt it has 14in wheels 225 is about as wide as you can go. never had any clearance problems. i think all fieros came with 195's stock. when you go taller and wider you need to watch on the rears or you will hit the spring pad on the strut.

no my fiero GT came stock with 205/60/15 in front, 215/60/15 in back.

maybe just 84's 85's did i dont know what mine came with it had 225's when i got it. the front tires do stick out a liitle more near the ground effects than the rears do because of the nose slanting inward. i think 235's would fit fine on the back but i might need wider wheels for that mine has the factory '85 14" wheels

oh and if anyone didnt know. the fiero's 14" aluminum wheels are wider than the same lookin wheels on the other pontiacs. the ones on my gt are anyways.

the stock GT wheels i heard are damn heavy, thats mostly why i wanna get rid of them, besides the fact that they are ugly