clemson_tiger

Ok, so I'm going to pick-up my new-to-me 19's Saturday and I want to be able to use my take measure to make sure they are going to work. I'm looking at the tire rack's website and they call for a +32mm and +35mm/+36mm "offset". They also say the backspacing should be anywhere from 5.74" to 6.14" for the front and 6.49" to 6.73". Now I'm a little lost...I thought offset was the same as backspacing...obviously not. LOL So, how can I/do I measure offset with my tape measure? If I measure the wheel and the backspacing falls with-in these ranges am I ok no matter what the offset is because the offset would have to be correct for the backspacing to be correct?

One final question and I think I've actually got the answer to this one...I should be able to measure the lug pattern (5x112) by measuring across the wheel, center of lug to center of lug (skipping one lug), and it should be just over 4 1/4", right? Like 4.40" exactly. I'm feeling pretty good about being able to determine this one.

Anyway, thanks for any advice guys. This is sort of a quick parking-lot measurment to make sure I'm not wasting my money. There's really no way to be certain on these wheels since I haven't seen them on a car, but the guy advertised them as coming off a 2009 SL, which according to the tire rack does have the correct offset and backspacing (and lug pattern obviously).

Thanks!

loudandheard

We have some wheel gurus on here and hopefully some one can chime in, but that is pretty technical. You can make any thing work, but you just have the right parts and money.

clemson_tiger

No, you're right...it is technical. I think though that if I know the wheel widths, which I do (8.5 & 9.5), then I should be able to use just the back spacing to be accurate. I think if my backspacing falls between 5.75" and some where around 6" on the front and 6.5" to 6.75" on the rears then offset must be right. Just looking for a little confirmation.

RLx02

You shouldn't worry so much.

I had the same tsw bremmas 19x8.5 front and 19x9.5 in the rear running 235/35 up front and 275/30 in the rear and they didn't run. The rears only rubbed when I had people in the back and went over a big bump or dip real fast.

take a look at my sig pic and you'll see what your car will look like, if you're on stock suspension

loudandheard

are these the SL wheels?

RLx02

the tsw bremmas are sl65 replica wheels.

C_DirtyTwo

Well if you think about it, stock SL wheels will fit on a C class no problem, and I believe the only 19" TSW Bremmas they could be are the 19x8.5(F) and 19x9.5(R)...which I have on my car, and many others have on their car...So I'd say not to worry about it and they'd fit....although I would not run a 275 in the rear, I'd stick to 265 max without some major fender modifications..

clemson_tiger

Well, the wheels are Bremma replicas (replicas of replicas LOL)...their Sport Edition, a Tire Rack house brand. They already have 235/35 and 255/30's so I'm not worried about the tire size. I basically just want to make a quick measurment with the tape measure to make sure I'm not buying a wheel that won't fit or I can't make fit with a spacer.

FrankW

back spacing is the measurement from the hub of your wheel to the back of the spoke.

offset is measured from the center of the wheel to the hub of the wheel.

for a C55 you have an extra 5mm on the front fender clearance vs the rest of the W203. to clear coilovers you will need at least a +28 offset. If you don't have the coilovers you will still need at least a +32 offset on a 8.5" front rim.

however back spacing can still be different even when two wheels have the same offset.

5x112 means it is 112mm from one bolt across to the other bolts. so what ever that is in inches.

Viper98912

I'm sure it was just a typing mistake, but it's 112mm diamater circle, not one bolt to another. In a 4 lug setup this is true, but not 5

RLx02

You don't major modifications to run 275's. My rear fenders are rolled and they didn't rub except for big dips with passengers in the back.

FrankW

yea, i meant the diameter...dunno what i typed earlier...lol