My Z3 is driving terribe someone please help

[Z3Chic18]

Hi, I recently just purchased a 1996 BMW Z3 so I'm extremely new to everything about the car( so please don't make fun if I did something stupid) lol anywayz I bought 2006 M5 wheels with 215/35/R18 tires the wheels have a 5x120 bolt pattern and a +20mm offset. The car is driving like crap and I don't why. The wheels are 18x8 & I figured maybe that's why cuz the tire is so narrow on that size but I'm not sure But before I bought all this I asked the guy at the tire place if they would work and he said no problem and put them on so then I thought well maybe they aren't balanced right. So anywayz I'd really appreciate if somebody could help me please and I did read that fitment thread

[Daved]

First, 215/35/18 is not the right size, you need 225/40/18

Second, I guess you mean 2006 M5 reps and not original wheels. +20mm is not the right offset for your car. And you still need to tell us the hub diameter.

Third, what do you exactly feel about driving terrible?

[Z3Chic18]

They were produced in an original bmw manufacturing facility, but they have a hub centric replica so I don't know. Anyway the employee at the tire place I go 2 said that +20mm would be fine, but then I looked it up on the internet last night and I'm suppose to have +25-55 apparently, but I wasn't sure if that website was right. Do u know exactly what size offset I'm suppose to have. Plus does 5mm really make a difference cuz I don't know. I've been driving on these things for a week and I just don't want anything to happen to me or tear up my car. ok about the tires could most of the problem be because of the size of the tires. It walks the road extremely bad and when I pass transfer trucks they almost blow me off side the interstate ok sorry please help oh and what did u mean how do I feel about it driving terrible it makes me sad if that's what u wanna hear. By the way I don't know the hub diameter.

[jr1966]

The Z3 is based on an E36 chassis requiring high-offset wheels. OEMs are 41mm but a range between 35mm to 47mm would work. Correct size for the tires given 18" wheels is 225/40-18. Hub diameter should be 72.56mm.

Offset of 20mm is very wrong for the car. And if you add in a hub diameter of 74.1mm (if they gave you a set of replica wheels designed for the E39), then it's gonna be worse.

The person you talked to obviously doesn't know what he's talking about.

You better get back there and ask to change to the right wheels and tires. Otherwise, get your money back.

[Z3Chic18]

Yeah I wish I could do that but now that they've been mounted they can't be returned thanx for telling me exactly what offset I need tho and yeah the hub diameter is 74.1 I remember seeing that number on the box they came in. ok well should i just put my old ones back on then. Do you think this has done any damage to my car?

[jr1966]

Yeah I wish I could do that but now that they've been mounted they can't be returned thanx for telling me exactly what offset I need tho and yeah the hub diameter is 74.1 I remember seeing that number on the box they came in. ok well should i just put my old ones back on then. Do you think this has done any damage to my car?

Confirmed they gave you a set of M6 replicas designed for the E39. If it wasn't for the offset, you could go by with hubcentric rings. However, even the offset is wrong.

It's their mistake so you have a right to return them even if they had been mounted and demand for the correct wheels or for a refund.

In the meantime, put back your old ones before damage to the steering & suspension components come up.

[z3papa]

I can't imagine how much of a dog a Z3 1.9 would be if it were turning 18" wheels given the added unsprung weight. Stock, they came with 16" wheels and while 18"ers will fill the wheel wells, they will not improve handling or performance. You may want to seriously rethink your modification.

[Jim@tirerack]

I agree with everyone. Take the wheels back. The offset and the tier size is wrong for your car. The center bore is incorrect as well if it was made for an E39 car.
If I can help let me know.

[jr1966]

I can't imagine how much of a dog a Z3 1.9 would be if it were turning 18" wheels given the added unsprung weight. Stock, they came with 16" wheels and while 18"ers will fill the wheel wells, they will not improve handling or performance. You may want to seriously rethink your modification.

You should see those 318s with 20" chrome wheels.:lol