Car swaying after changing wheels and tyres

[sustrafics]

Originally Posted by Gpwheels

I notice you tires are different height. The 35 in your size is a ratio between your sidewall and your width. Even with staggered fitment, your tire circumference should be the same. This could affect your ABS and traction control. The swaying may be the car trying to correct what it thinks is a spin or a slide. You may need a 275/30/19 in the rear to balance the fronts out, but that might be too wide for your rims

Thanks for your answer. Do you think 225/35/19 tyres will fit the 8.5 inches front wheels? Or will it be too stretched?

[sustrafics]

Originally Posted by rking117

That is definately tramlining. The less meat you have between teh tire and the rim the more yuo will fell the tramlining.

The problem is that I have already driven other cars and didn't feel it. That is my problem...
I am planning to buy new tyres. But I am "affraid" that I will spend a lot of money and the problem persists. Should I get rid of these wheels?

[nicknaz]

Originally Posted by sustrafics

Thanks for your answer. Do you think 225/35/19 tyres will fit the 8.5 inches front wheels? Or will it be too stretched?

It should be ok.

That size tire is on an 8 inch wide wheel from the factory and there is a range of wheel widths that is acceptable.

If you are getting new tires anyway, 235/35/19 and 265/30/19 has been posted by many other forums members as working well.

[sustrafics]

Originally Posted by nicknaz

It should be ok.

That size tire is on an 8 inch wide wheel from the factory and there is a range of wheel widths that is acceptable.

If you are getting new tires anyway, 235/35/19 and 265/30/19 has been posted by many other forums members as working well.

Thanks for your help. The problem is that here in my country those tyre measures are not approved in the E89. At least in the papper that I have to show to the cops those measures are not approved. That's why I am going for the stock measures...

[nicknaz]

Originally Posted by sustrafics

Thanks for your help. The problem is that here in my country those tyre measures are not approved in the E89. At least in the papper that I have to show to the cops those measures are not approved. That's why I am going for the stock measures...

Yes, going to stock is a good idea. Or at least, if you don't do the stock size make sure the difference in tire diameter between the front and rear is similar to stock.

The stock 18" staggered tires have a 0.2% difference and the stock 19" staggered tires have a 0.7% difference

If I was in your situation, I would not have gotten the 255/35/19 rear tire in the first place. That is about 3% difference from the OEM tire diameter and your combination of tires has 2% difference in diameter between the front and the rear.

As others have pointed out, there difference in rotation speeds between angles is one of the inputs used by the car's stability control system. I am not sure on the acceptable tolerance for the difference in front and rear tire diameter, but I am GUESSING (as others have) that your tires have too much difference.

[sustrafics]

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[sustrafics]

Originally Posted by nicknaz

Yes, going to stock is a good idea. Or at least, if you don't do the stock size make sure the difference in tire diameter between the front and rear is similar to stock.

The stock 18" staggered tires have a 0.2% difference and the stock 19" staggered tires have a 0.7% difference

If I was in your situation, I would not have gotten the 255/35/19 rear tire in the first place. That is about 3% difference from the OEM tire diameter and your combination of tires has 2% difference in diameter between the front and the rear.

As others have pointed out, there difference in rotation speeds between angles is one of the inputs used by the car's stability control system. I am not sure on the acceptable tolerance for the difference in front and rear tire diameter, but I am GUESSING (as others have) that your tires have too much difference.

Thank you for your clear answer. I will change to stock tyres, then. Do you think the wheels being all the same size is not creating the problem?

[nicknaz]

Originally Posted by sustrafics

Thank you for your clear answer. I will change to stock tyres, then. Do you think the wheels being all the same size is not creating the problem?

That would not create any problems. As far as I understand it only way the wheels could create a problem is if they are cracked or bent or if a wheel weight has fallen off

At the risk of stating the obvious, you can change the brand of tire with no issues, just make sure the sizes make sense

[raven333]

Originally Posted by sustrafics

After some time has passed, the problem persists. I am planning to get back to the 18'' wheels. The dealer says that my problem must be related to the wheels size (8,5 inches square set) and tyres being too large and non RFT. They say that I should be driving RFT as they are much more secure and I wouldn't feel that strange feeling of swaying. What do you think so?

You cannot run 19" without an offset front to rear, so saying that your 19" wheels are 8.5" all round is why you are having a problem.........This is not even including any disparity in tyre size.........

[nicknaz]

Originally Posted by raven333

You cannot run 19" without an offset front to rear, so saying that your 19" wheels are 8.5" all round is why you are having a problem.........This is not even including any disparity in tyre size.........

I think that's a bit of a blanket statement...

8" wide wheel with ET29 offset works front and rear (ie oem style 290).

8.5" wide would be ok for a "square" tire setup if the offsets were appropriate.

[Gpwheels]

Also, don't buy the part about going back to RFTs. Lots of people are running non-RFTs and have no issues. Most people prefer them.

[raven333]

Originally Posted by nicknaz

I think that's a bit of a blanket statement...

8" wide wheel with ET29 offset works front and rear (ie oem style 290).

8.5" wide would be ok for a "square" tire setup if the offsets were appropriate.

Hi ! Agree with the use of blanket statements with little supporting data but in this case I know someone who tried to use 8.5" square 19" wheels on all four corners and had real issues, he only drove it for some 20+ miles, contacted his friend a BMW mechanic (he was in a bit of a panic) who told him that it would always be a problem with that configuration and to remove them as it was not worth it, it is not the rears that are the issue it is the fronts..........it upsets the geometry somehow, but I do not know how???
Personally I thought you could not get 8.5" /19" upfront as they will not fit without using spacers anyway?????

[sustrafics]

Originally Posted by raven333

Hi ! Agree with the use of blanket statements with little supporting data but in this case I know someone who tried to use 8.5" square 19" wheels on all four corners and had real issues, he only drove it for some 20+ miles, contacted his friend a BMW mechanic (he was in a bit of a panic) who told him that it would always be a problem with that configuration and to remove them as it was not worth it, it is not the rears that are the issue it is the fronts..........it upsets the geometry somehow, but I do not know how???
Personally I thought you could not get 8.5" /19" upfront as they will not fit without using spacers anyway?????

I thought the problem had to do with the tyres and not the wheels...do you think I should get rid of them? I really like the way they look, because they are the most similar to 326M wheels I could find. It was impossible to find the original 326M to buy!!

Thanks for your help...

[nicknaz]

Originally Posted by sustrafics

I thought the problem had to do with the tyres and not the wheels...do you think I should get rid of them? I really like the way they look, because they are the most similar to 326M wheels I could find. It was impossible to find the original 326M to buy!!

Thanks for your help...

If I was in your shoes, I would not change the wheels if there is no rub. As a double check, look at the offset of your new wheels to see how much different they are from the wheels others have been using on their E89

[sustrafics]

Originally Posted by nicknaz

If I was in your shoes, I would not change the wheels if there is no rub. As a double check, look at the offset of your new wheels to see how much different they are from the wheels others have been using on their E89

There is no rub at all. The problem is just tramlining and feeling that the car is not what it used to be when It was on 18" wheels. If I could find a good deal for 326M wheels I would change...the problem is that they are very rare!

[Gpwheels]

Unless the wheels are damaged, they should be fine, but you probably need different tires. If you are unsure about sizing, go to a reputable tire shop (doesn't have to be BMW) and ask them what sizes they recommend. They should be able to recommend a staggered fitment with the same diameter or circumference. A good tire shop should also warranty the fit, so if they don't drive well, they would change sizes or suggest spacers or an alignment. If you are not worried about being stranded with a flat, I would stay away from RFTs. The stiff sidewall compromises handling and ride quality and you pay a premium for them (just don't get a flat).

[sustrafics]

Originally Posted by Gpwheels

Unless the wheels are damaged, they should be fine, but you probably need different tires. If you are unsure about sizing, go to a reputable tire shop (doesn't have to be BMW) and ask them what sizes they recommend. They should be able to recommend a staggered fitment with the same diameter or circumference. A good tire shop should also warranty the fit, so if they don't drive well, they would change sizes or suggest spacers or an alignment. If you are not worried about being stranded with a flat, I would stay away from RFTs. The stiff sidewall compromises handling and ride quality and you pay a premium for them (just don't get a flat).

Thanks for your answer. Do you think the previous statements saying that square set is incompatible with the z4 are something to worry? I really like to have the car in a perfect way. If I need to replace to the previous wheels again, I will do it. Thanks for you help

[sustrafics]

After thinking a bit, I have decided to go back to my 293 wheels. Maybe I will sell or trade the set of 351M wheels and buy the original set of 326M. Do you know someone interested in a trade or another kind of deal?
Thanks!

[sustrafics]

Hey! I have finally replaced the tyres for new ones with the OEM measures and everything is solved. I have the car back! It does not sway anymore and its behaviour is completely different. I have changed to 225/35/19 front and 255/30/19 rear bridgestone potenza Rft. It is hard, but it is finally not having that strange behaviour...

[raven333]

Really pleased you got it sorted, nothing worse than driving a car that feels unsettled on the road. It seems that my comments proved correct in this instance, but I am sure someone will argue differently. The main thing is you are now happy with your car!!!!!!

[nicknaz]

Originally Posted by sustrafics

Hey! I have finally replaced the tyres for new ones with the OEM measures and everything is solved. I have the car back! It does not sway anymore and its behaviour is completely different. I have changed to 225/35/19 front and 255/30/19 rear bridgestone potenza Rft. It is hard, but it is finally not having that strange behaviour...

[Gpwheels]

Glad to hear it's fixed. If the ride is too harsh, next time you change your tires, go with non-RFTs in the same size. Probably better just to drive it for a while and enjoy it.