couldnt decide where to put this question, but how much of a difference does it make on the speedo when you switch from a 16" rim to a 17" rim?

 

None, as long as you put the right sized tires on the car.

 

what would be the right size im looking at a set of tires, if you dont mind me asking?

 

I think for 17s it is 245/45/R17

 

ok thanks for the answer

 

Not a problem :-)

http://www.miata.net/garage/tirecalc.html

You can use that to see the size differences in different tires.

 

Look at the overall diameter of your stock 15" or 16" tires, then find a 17" tire that fits the new rim, but is as close as possible to the original tire.

Look on Tirerack.com, to compare sizes, and look into the +1/+2 selection.

 

ok one more question, will these fit with the 245/45/r17
http://hawksthirdgenparts.com/index....ROD&ProdID=480

 

Yes. A 245 on a 8" rim is the ideal width.

 

thanks for the quick answer im gonna go with those

 

245s were the stock width on the stock 16" x 8" rims. 255s fit quite nicely too. Which is the widest 16" street tire you can get, unless you jump to the 295/50s, which is the MAX or our 16" x 8".

Some people will tell you you can't do it, but I have before, a buddy has them now, and I'm only waiting for my current 245s to wear out.

 

the 245/45/17 and 275/40/17 combo is very popular. Its what im running, and they only vary .02 of an inch or something like that.

However, i think our cars are supposed to have 235/60/15 tires on. Not sure what the the height of that is, but if you look at the sticker in your door, it will tell you what you SHOULD be running, try to match it to that.

 

That depends on the car. However, the cars that got the V rated 16 inch tires got a 245/50/R16.

https://www.thirdgen.org/1984-pontiac-firebird

They started using them back in 84

 

thats what my car has

 

ok, 245/50/16 is only off by 0.1" from 245/45/17 and 275/40/17.

The latter two, are almost identical. Off by about 0.02". So if u want to run those, its prolly ur best bet.

 

I'm running 275/40/17s front and rear. I didn't notice any variation in the speedometer.

 

25.7" OD is I think the target rotating diameter. Less or more will scew with the speedo. I'm running 17's and the 245 front / 275 rear deal. ALOT of us do that. 18's are nice too but I can't bring myself to spend the money on the "correct" setup knowing 1 good New England pothole could cost me big money to fix.

 

25.7 is stock

AC, i bet ive got bigger potholes down here

 

86TA, true that...you have the potholes that result in a 12 second ETA to drive into and then out of....LOOOOONNNNGGGG potholes. I was in Ocean City last summer for a few days in the ol' minivan and I dropped into a few and was like "what the f was that"...only to say 4 seconds later "what the f was that" not realizing I was exiting the pot hole I'd hit 4 seconds eariler.

 

what is your rim backspacing and do they tuck under the car right? i have a 1989 firebird looking for some 17s 5 spoke and 275/40/17s thats what i had on my ole ladys 95 rustang and it looked great so...if it looket great on a ford should look awesome on a bird. also kinda off topic but what about speedo gears to correct for oversized tires i have owned 5 of these cars and went from 273s to 373s and 275/60/15s in all of em just never found a replacement gear to fix the speedo even if i go to 17s im gonna have to find someone to sell me the gear for the 3.73s