Ive looked at the FAQ's and looked at various forums trying to find out what kind of rims I could get. I want a wide tire like 215 or 225 but noticed that these wheel websites when searching by your car model, make, year, you only get returns like 205 or 195.

Now Ive seen in some posts that if you take into consideration things like offset, and rim width you can get a good width tire up under a J!, like 235 .

Ive also noticed that different rim widths can accomodate the same tire width like,
17" x 7.5 & 17 x 7 rim with a 225 tire. Now Im guessing that tire sidewall heght may have something to do with it. but can someone clarify?

What, if any, is the formula, I guess for knowing what width tire will fit on what width rim?

Thanx guys.

i read this like 3 times and im still not sure on what your tryin' to ask

LOL, alright say I want a 235 tire, how do I know what width rim I should get?

I think it will fit a 7.5 and up to like a 9.5, but no promises. BTW 235mm = 9.25in.

alright, say I have a 7.5" rim. what the largest width I can get on a tire 215? 225? 235?

the only way you can find this information out is by looking it up in the tire specs. find a tire you are interested in first.

first off, you will have to find a tire size that is comparable in diameter to your original. the reason for wanting a tire with a similar height to the original is simple and complex at the same time. alot of things can be affected by choosing the wrong size tire. mainy your speedo will be useless, your revs and rev limiter can be severly compromized, your abs can be deemed useless as well, and for tires over 5% over or under original size, your abs computer will take a serious licking and may even crap out on you. dont even get me started if it is alwheel drive.

there are a few very good calculators on the internet, but wild weasel has been kind enough to host a very good one for our use. so everyone take the time to thank him, lol.

http://www.wildweasel.ca/j-body/HowTo/

i believe the instructions for the calculator are straight forward, i havent had a need to use weasels one yet

second, you want to pick a tire in that size now. for this we will use the ever reclusive tirerack.com where you can search for tires by saize as well as brand.

once you have found the tire or tires you like you need to look at the specs for each of them. the specs will show for how wide of a rim each manufacturer says a tire can fit on. it is important to know that a pecific model and brand tire size may not be the same specs for other tires within the same sizing in another brand or even the same size in a different model of the same brand.

so forexample, lets take the BFG G-force Sport, one of my favourites. in the size 205/55R16, which is standard on the 3rd gen Z's and GT's. that tire is rated to fit on a 5.5" to a 7.5" wide rim. now the rims for the 3rd gens i believe are 6" wide, might be 6.5" i cant remember.

now there are other things to consider as well. a tire can be able to mount on 5.5-7.5" wide rim, but it is important to know what size rim they have rated that tire on. that particular tire is rated on a 6.5" wide rim. when installed on that wide of a rim, the tire's sectinon width should measure 8.4" wide. that would equal almost 215mm of rubber on the road.

some brands rate the tires they make on very small rims. i had a set of Michelin Energy MXV4+ and they measured out huge on my original 6" steelies. i was laying down like a 225 mm contact patch.

now this is an important thing to consider because you could end up with the exact tire size and rim width combo as your buddy, but because you went with a different model that rates their tires differently, you will rub on something.

for figuring this stuff out, use the tire calc i made. it will measure how wide a certain tire will measure on your width of rim by punching the specs into an excel spreadsheet. it also has an offset calc on it.





Injection is nice but id rather be BLOWN!
http://www.cardomain.com/ride/2290307

You can put ALMOST any tire on any wheel within reason if you do not care about your speedo being off or possibly "putting more miles on your vehicle". Take my truck for instance... I have a 205/50/16 on a 16 x 8.5 wheel.


-Brandon

I'm getting 225s on my 7.5s, I wouldn't go any bigger than 235.

Thanx Whitegoose for clearing that up!

www.tirerack.com

Go to specs, it will have the tire sizes, and the wheel width range.


Just a note, you can run any size starting from that minimum width up to about 3-4" wider, it will look stretched, but some people like that.

Just... go to tirerack and look at tire sizes and specs, you'll learn a lot about fitments.