Wheel Offset

[Arro]

A VERY common question on this forum is if a wheel will fit. The real concern isn't diameter, but OFFSET.

Offset is how we measure the center surface that mates with the hub.



Our wheels are a low positive offset. Most FWD wheels are a higher positive offset, and many oldschool RWD vehicles use a zero or even negative offset.

It's important to note that the stock wheels are +35. It's also important to know that in stock form, the stock wheels are sunk into the wheel well.

Generally a common size is 7" wide, zero offset. This usually fits nearly flush (maybe a milimeter or two over). With the rear suspension dropped some, the rear tires will easilly tuck in.

But another thing to note is that the fender lip on the front is not as far out as the fender lip on the rear. This is actually true of S13, S14, Z32, Z33, Z34, G35 sedan, and even 1G Z cars like the 240Z through the 280Z. What this means is that you can run wider wheels/tires in the rear and be flush.... what they call a "staggered" wheel set.

So how do you calculate the proper offset to get the best fitment?

Here is a handy calculator to do just that!

http://www.1010tires.com/WheelOffsetCalculator.asp

You input the specs of your wheels as they are now. You then input the specs of the proposed wheels. It gives you the extra depth and outside measurements. Go and grab the ruler and eyeball the shocks on the inside, and the fender lip on the outside.

[brewster240]

i think this goes hand in hand with this:

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

[Arro]

Yeah, except that it doesn't show tire width vs. wheel to illustrate stretch vs. balloon... then again that fluctuates with brand and model of tires.

[brewster240]

i just noticed you posted a calc in yours, i skipped over that somehow.

i guess delete mine if you want to clean this up.

wait, yours is an offset calc.

i guess thats a sign for me to go to sleep

[Maxpow]

I've got the best one hands down, been using it since I had the eclipse:

http://www.wheelsmaster.com/rt_specs.jsp

[Micro S12]

IÃ,´m thinking of getting a set of steelrims widened.
But I dont know how wide and what offset they should be when they are done.
Can anyone help me with what offset and dimensions i should order?
And what is the widest you can squese in?
Width:
Offset:

Were thinking of getting stretched tires for them later.

[Xano]

there are people running 9" wide in the back i believe. and 8" in the front fits ok.

i know that my 7" 0 offset wheels poke out a tiny bit on the front, and are a tiny bit sunken in on the back.

So use that as you will. 

[Arro]

You can run 9" wide tires in the back if your offset is no lower than -10. To run like that, you're gonna have to run a mad stretch with like 205 width tires in order to clear the rear quarterpanel lip. So what's the point?

All you really get for going with a 9" low offset wheel in the rear is more expensive wheels to buy, and screwing with the offset. Unless you're gonna run fender flares, stick with 8" max width and zero offset (which is more common and less expensive).

If you want to run wider, just don't go "hellaflush", and keep the offset closer to zero. Then you also get the advantage of running with wider tires.

Also, your ride height determins the angle of the suspension and thus how the tires will fit when flush. Keep this in mind.

[Maxpow]

Fender flares, -15(or more) offset, 315's in the back, 275's up front.


That would be hawt.

[EightySix200SX]

Lol just wait you'll see

[sam31183]

i need to test fit all 4 of those steelies/slicks on the car....lol.

[Arro]

Keep the discussion on the specifics of offset, any examples should be seperate threads.

[iceageg]

As I troll through the archive of knowledge that is burried in these forums I noticed that there are a couple things worth mentioning here.

First, using wheels with an offset improper for your vehicle can greatly impact the life of your wheel bearings.  This is usually more of an issue in heavier cars and trucks, but still worth noting.  As light as S12s are they likely allow for quite a bit more wiggle room to deviate from this general rule.  The closer you can stay to the original configuration the less contribution your wheels will have on the bearing life.

Second, you noted above that FWD vehicles usually have a positive offset and many RWD use zero or negative offset.  Some of the more exotic AWD cars like Lamborghinis have used positive offset on the fronts and negatives on the rear of the same vehicle.

[silverton]

Nissan just seems to like using positive offset wheels.  s12, z31, z32, wd21, etc etc.

[nismo_200sx]

i want true 16x8 all the way around but i want a flush fit. no sunken in look and not too much plus offset. also no rubbing whatsoever. can you guys help?
i put 16x8 +12 cause if i have +0 it will hit the struts and stuff when im lowered wont it? i dont mind staggered but i just would prefer the same all the way around you know in case i flip them around when i put different tires on etc since i will be drifting.
i used the original comparison link arro had put up. i wouldnt mind a mild stretch so could i run 205's or run 195's on 8 inch wide? also would +12 offset have some sort of lip? i like lips.

[silvia love]

an 8'' wide rim with a zero offset and 205/55r16's will rub like a mofo on our rears

8'' wide rim with +15 offset up front fits good with a little neg camber, stock camber rubs on 205/55, which should roughly fit the same as a 7'' wide rim with a zero offset and same height tires

rim width is as important as offset when going for a flush fitment. a 15*7 et 0 and a 15*8 et0 will fit differently, it would be like having a 15*7 et -15 or so to match the extra inch in width.... just had to throw that out there in case some are still confused

[Arro]

I have 7" wide and zero offset with 195's and they don't clear without some negative camber... I have 205's on the same wheels in the rear, and when I tried those 205's in the front, there was no way the would clear the fenders even when I maxxed out my top camber plates negative.

basically an 8" wide rim with +15 is not going to fit with a 205 tire on the front. 195 with 2 degrees neg. or more, maybe.

But he wants more of a flush fit, not something that pokes until you tuck it in with camber. Chances are, he doesn't have camber plates at the top. So the reality is, he shouldn't be running an 8" wheel in the front at all, because there just aren't many 16x8 or even 15x8 wheel choices in an offset that would be the right fit that he wants... to run 8" and flush in the front, he needs something closer to our factory offset. Keep in mind or factory wheels are 6" wide, so add another inch outward with the same offset (to get an 8" wide wheel) and you have flushness.. only, it won't clear the strut tube.

What I'm getting at is an 8" wheel that's close to flush is just not a realistic option, 7" is a better bet for the front. This is also why IMO, if you are worried about traction, go staggered with 8" all around.

The exception to this would be super-stretched tires, massive negative camber, and probably some major fender pulling.

[Athens]

Cut the fender and run ZG Flares off a 240Z. You'd probably be able to fit an 8" in the front with that, granted you have the optimal offset and tire size.

[Deezus]

First, using wheels with an offset improper for your vehicle can greatly impact the life of your wheel bearings.

everything we do to cars is bad for them.

[nismo_200sx]

I have 7" wide and zero offset with 195's and they don't clear without some negative camber... I have 205's on the same wheels in the rear, and when I tried those 205's in the front, there was no way the would clear the fenders even when I maxxed out my top camber plates negative.

basically an 8" wide rim with +15 is not going to fit with a 205 tire on the front. 195 with 2 degrees neg. or more, maybe.

But he wants more of a flush fit, not something that pokes until you tuck it in with camber. Chances are, he doesn't have camber plates at the top. So the reality is, he shouldn't be running an 8" wheel in the front at all, because there just aren't many 16x8 or even 15x8 wheel choices in an offset that would be the right fit that he wants... to run 8" and flush in the front, he needs something closer to our factory offset. Keep in mind or factory wheels are 6" wide, so add another inch outward with the same offset (to get an 8" wide wheel) and you have flushness.. only, it won't clear the strut tube.

What I'm getting at is an 8" wheel that's close to flush is just not a realistic option, 7" is a better bet for the front. This is also why IMO, if you are worried about traction, go staggered with 8" all around.

The exception to this would be super-stretched tires, massive negative camber, and probably some major fender pulling.

so a 16x7 +12 195 in the front work out good? no rubbing strut tubes, fenders, etc, and 16x8 +12 in the rear with 205 work the same way? complete fitment no rubbing dope looking.