wheel + tire diameter

[89camaroperson]

A buddy of mine has a 98 z28 and bought new tires for it a few months ago. He just bought z06 wheels and tires so now hes got some nice bfg g-force z rated tires sitting around on 16" wheels. Id rather not even try to fit his stock wheels on my car with spacers because of the possibility of somthing breaking. what is the overall tire dimension for a fourth gen and is it the same for a 3rd gen. I wouldnt think so but maybe. Id probably have to change the speedo gears to make it all work together. Id have to get new wheels too and thats fine with me. Anybody have a clue?

[wrightz28]

I don't think it's the overall hieght and width that kills it, nor is it really a spacer you need, I think it's an adaptor due to slightly different bolt spacing.

[89camaroperson]

but im not going to use the wheels just the tires. they are 16 " 245's so that will also be a sqeeze on my 89 3rd gen.
here is the wheel i currently have and would like to keep because i really like them.
http://www.americanracing.com/wheels...ated&section=A
i just dont know if they will fit because of a diameter increase(if there is one) and their width. I know ill have to cut some stuff to clear my turning radius because they are 245s but i dont know what else

[89camaroperson]

the wheels and tires i have now are 15" 235 radial t/a bfg's

[wrightz28]

Oh, ok, now I got ya,

No, you have 15" rims. A 16" tire isn't gonna work for ya bud.

The 245 would be ok, I've run 255's on mine.

[wrightz28]

Oh, ok, now I got ya,

No, you have 15" rims. A 16" tire isn't gonna work for ya bud.

The 245 part would be ok, I've run 255's on mine.

[89camaroperson]

yes....but....say i buy a 16" rim....same style as the one i currently have
http://www.americanracing.com/wheels...ated&section=A
like those....will it be the same diameter as the tires i currently have....that it what my question is... that and is it difficult to change speedo gears if it is neccessary....and with that added diameter will they fit in the front wheel wells and not rub when i turn my wheels.

[wrightz28]

That would all depend on the aspect ratio (side wall height).

Honestly, instead of crackng a keyboard about it dude, set the two up next to each other, but I honestly don't think you'll have problems unless you have some really weak steering or suspension components. Turning radius should be fine.

And if the overall height is not all that off there may be little difference in speedo calibration. Which honestly I don't think there's really anything you can there. Would be no different than having a 3.73 gear in it, you just learn to live with it.

[89IROC&RS]

my IROC has the 16in rims and 245 tires from the factory, those tires will fit in your car just fine. We can even fit larger tires in there if we want to.

however if you are going to use fourth gen camaro rims, you will need wheel spacers because of different backspacing on the mounting flanges.

also, the speedo can be calibrated for different rear gears and tire sizes. but i would leave that job to a transmission specialist who knows how to pick the correct gears. There are two gears in the tailshaft of the tranny, one is a drive gear and one is a driven gear, and by combining different gears you can accomidate different size tires and gears and have a correct speedo.

[wrightz28]

They must hodge podging the ration of the gears. Closest I could get mine was within jsut over 2% error reading?

Be honest with ya, I don't even pay attention to the speedo that much anyway.

[Genopsyde]

TGO has a chart for selecting proper speedo gear combo's.

[NoRiceHere01]

i think our moderator has pretty much cleared it up, but i figured u could use this for the future anyway.
the first number on the tire is the width in millimeters. the second, or aspect ratio, is the relationship of height to width of the tire. for instance, a 245/45 is 45 percent as tall as it is wide. a 245/50 is 50 percent, so its the same width, just slightly taller.
if u can fit a 235 on ur car, a 245 will fit. its only 10 millimeters. u can hardly even see the difference. sorry to be a know it all, just had to get that out lol.

[bag91]

235's for 15" and 245's for 16".

[stepho]

Originally Posted by NoRiceHere01

...the first number on the tire is the width in millimeters. the second, or aspect ratio, is the relationship of height to width of the tire. for instance, a 245/45 is 45 percent as tall as it is wide. a 245/50 is 50 percent, so its the same width, just slightly taller....

im confused. The height, for the aspect ratio, is the diameter of the side wall?

[NoRiceHere01]

its the width of the sidewall, from the surface of the tire to the bead, where it meets the rim.