So, I'm pretty good at engine work... and though I've never done it, I have a good understanding about transmissions. All the other general maintenance items around the car I'm pretty good with too.

Except wheels and tires. I'm completely retarded about them.

I don't understand what all the numbers for tire sizes are. I have only a vague idea of offsets on wheels. And can any 5 bolt wheel fit on any 5 bolt hub?!

If some of you would be so kind as to edumacate me. I'd be grateful.

P.S. Where this is eventually going is when I do buy an '85 Toronado I'd like to try and find a set of tasteful alloys that could fit the look of the car. I don't mind the standard wire spokes that come with it except they are strangely noisy. I'm not going to donk it, but I might want to go up to 16s or 17s.

So, I'm pretty good at engine work... and though I've never done it, I have a good understanding about transmissions. All the other general maintenance items around the car I'm pretty good with too.

Except wheels and tires. I'm completely retarded about them.

I don't understand what all the numbers for tire sizes are. I have only a vague idea of offsets on wheels. And can any 5 bolt wheel fit on any 5 bolt hub?!

If some of you would be so kind as to edumacate me. I'd be grateful.

P.S. Where this is eventually going is when I do buy an '85 Toronado I'd like to try and find a set of tasteful alloys that could fit the look of the car. I don't mind the standard wire spokes that come with it except they are strangely noisy. I'm not going to donk it, but I might want to go up to 16s or 17s.

There are different lug patterns, even within the same number of lugs, so no, a 5 bolt wheel may not fit any particular 5 bolt pattern. Being a Saturn S-Series guy, that's more what I know. So, for example, the S-Series has a 4X100 (I believe that's 100mm) pattern. This happens to be shared with a number of other cars, including the Ion, Civic, and many others. There are other patterns, though, which is why some aftermarket wheels have 8 lug holes in a square - it is made to fit two different 4-lug patterns. There can also be issues with offset, but I'm not sure I can explain that well, but even if a wheel has the same lug pattern, there is a chance it may still not fit right due to the offset.

i know most older chevy cars, such as my nova for example, have a 5x4.75 bolt pattern, meaning 5 lugs, in a 4.75in circumfrence circle.... i m not sure about the toronado but it may be similar..

offset/backspacing is the space from the rear lip of the rim to the rear mounting face the hub bolts to.... so the offset determines how far in/out of the wheel well the rim sits.. when you see a car with the rim two inches past out the fender lip, the owner doesnt know about backspacing...

The lug pattern may be in inches or mm, depending on your car.

Civic = 4x100, some old Accords = 4x114.3. The stupid dealer who sold me my Integra (4x100) included an Accord (4x114.3) spare tire. lol

Tire sizes go like this: 225 55 16

225 is the width in mm, 55 is the sidewall height as a percentage of the width, and 16 is the size of the wheel in inches.

Edit: I hope my memory serves me.

Edited December 11, 200718 yr by siegen

you're right siegen. first number is width, second is aspect ratio, or the percentage of sidewall height to width, third number (typically has an R in front of it) is the actual center hole size in inches.