Car swaying after changing wheels and tyres

[sustrafics]

Hello!

I am experiencing a problem with my z4. I have switched from 18" 293 style wheels to 19" 351 (5 series original wheels), being these new wheels all the same size. They came from a 5 series Xdrive. It was a great deal, so I picked them up. After replacing to the new wheels, the car feels very strange. At high or even low speeds, when I find some irregularities on the road (like those white lines separating the roads) the car sways a lot, feeling like it takes its own direction! If I do not hold the steering wheel firmly, it takes another direction other than straight. I have always loved the way the car drives. Now it feels like it is not the same car anymore. Can you help me?
The tyres are correctly aligned. The tyres are not the correct measure, because there were no available tyres at the moment. I have 235/35/19 front and 255/35/19 rear. The wheels are four squared.
Do you think the problem are the tyres or the wheels?
Thanks a lot for your help!

[pete_z89]

Originally Posted by sustrafics

Hello!

I am experiencing a problem with my z4. I have switched from 18" 293 style wheels to 19" 351 (5 series original wheels), being these new wheels all the same size. They came from a 5 series Xdrive. It was a great deal, so I picked them up. After replacing to the new wheels, the car feels very strange. At high or even low speeds, when I find some irregularities on the road (like those white lines separating the roads) the car sways a lot, feeling like it takes its own direction! If I do not hold the steering wheel firmly, it takes another direction other than straight. I have always loved the way the car drives. Now it feels like it is not the same car anymore. Can you help me?
The tyres are correctly aligned. The tyres are not the correct measure, because there were no available tyres at the moment. I have 235/35/19 front and 255/35/19 rear. The wheels are four squared.
Do you think the problem are the tyres or the wheels?
Thanks a lot for your help!

I honestly cannot say what is causing the problem. However, I can relate. My Z4 is about 3-4 months new to me, 2 years used from original manufacture date. And every now and then (definitely not a recurring thing though), I'll notice the exact same thing that you're talking about. But this is with the stock 18x8 front and 18x8.5 rears with 225/40 and 255/35 runflats. It used to be slightly annoying, but now I've gotten past it. It happens maybe a couple times per week.

I'm hoping that upgrading to my Alufelgens this upcoming weekend with new tires will solve the problem. I know this was no help whatsoever, but I thought I would post because I've experienced the same problem. Let me know if you find a solution!

[Swervd]

Do the wheels roll straight when off the car? Could be out of balance. I would check tire pressure and lug bolts for tightness. If that's not it, I would take it in to have balance and alignment checked. Hope that helped

[nicknaz]

I agree with everything the others have said. One other minor point to consider is that if you have gone to a wider front tire, the car could be "tramlining" (i.e. following the grooves in the road more closely)

[sustrafics]

Originally Posted by Swervd

Do the wheels roll straight when off the car? Could be out of balance. I would check tire pressure and lug bolts for tightness. If that's not it, I would take it in to have balance and alignment checked. Hope that helped

Thanks for your answer. Indeed, I have already checked all those points you have mentioned. It was everything correct. The problem must be on the wheels or tire measures. I would like to have an opinion of which of the two could be causing the problem. Hope that are not the wheels fitment =\

[jts1981]

Lower profile and wider tires will follow the natural curves , bumps of the road. It's the stiff side wall and limited flex that make the tire stick to the road.

Also tire tread pattern affects this as well.

I worked at Sears tire and we learned this during training.

[sustrafics]

Originally Posted by jts1981

Lower profile and wider tires will follow the natural curves , bumps of the road. It's the stiff side wall and limited flex that make the tire stick to the road.

Also tire tread pattern affects this as well.

I worked at Sears tire and we learned this during training.

Thanks for your answer. So you are saying that the "problem" is related to the tires and not to the wheels? I have already driven other 19" wheels equiped cars and their behaviour was not like this. I had never felt car swaying with the previous set of 18" wheels. Dealer can't help me because he says I am driving a square set of wheels and not the staggered that was supposed. Do you think this can afect the way it drives?

[tamkhan]

I have the 18" RFTs that came with the car (M package) and I have the exact same issue. I just thought it was because RFTs have a more uncomfortable ride and pick out all the details on the road. Even when I brake from high speed, the steering just abruptly turns to one side. Sometimes I feel like I'm battling with the steering as I drive

I guess I should get the alignment and tire pressure checked.

[sustrafics]

Originally Posted by tamkhan

I have the 18" RFTs that came with the car (M package) and I have the exact same issue. I just thought it was because RFTs have a more uncomfortable ride and pick out all the details on the road. Even when I brake from high speed, the steering just abruptly turns to one side. Sometimes I feel like I'm battling with the steering as I drive

I guess I should get the alignment and tire pressure checked.

That is exactly the same feeling I get. But I had the 18" wheels and never felt that =\. I thought it was because of the new 19" wheels. Forget it...I have already checked everything from alignment to pressure and it is everything perfect. It feels like it is a different car now.

[ManiacGT]

Let the car settle in a bit on the new tyres. Mine was a bit unsettled when changing to PSS but after a week or two it settled down just fine and is so much sharper after a hunter 4 wheel alignment plus the PSS.

[sustrafics]

Originally Posted by ManiacGT

Let the car settle in a bit on the new tyres. Mine was a bit unsettled when changing to PSS but after a week or two it settled down just fine and is so much sharper after a hunter 4 wheel alignment plus the PSS.

Do you think that the wheels are ok? Isn't it a problem being a square set?

[ManiacGT]

I doubt the wheels being the same size will hurt. Offsets might have a slight impact but it shouldn't be that bad.

[sustrafics]

Originally Posted by ManiacGT

I doubt the wheels being the same size will hurt. Offsets might have a slight impact but it shouldn't be that bad.

Thanks! The dealer is saying that it might be the wheels, but I Don't think so. Do you think some spacers would make it handle better?

[Crazykoh]

Were the tires from the 5 series as well? If so, any difference in the camber of the alignment and where on the car the tire was placed might make for some strange feelings because of the wear pattern on the tires.

[ManiacGT]

Originally Posted by Crazykoh

We're the tires from the 5 series as well? If so, any difference in the camber of the alignment and where on the car the tire was placed might make for some strange feelings because of the wear pattern on the tires.

+1 on that. If the tyres were not new then the pattern will be worn as per the 5 series setup and that could take quite some time to wear down. If they're new then there should be no issue related to the tyre.

[sustrafics]

Originally Posted by ManiacGT

+1 on that. If the tyres were not new then the pattern will be worn as per the 5 series setup and that could take quite some time to wear down. If they're new then there should be no issue related to the tyre.

Yes! The tyres were not new. They were from the 5 series as well. Maybe this is creating the problem. They were included in the price, so it was a really great deal! Do you think spacers and new tires would make it good again? Or wouldn't you put spacers?

[ManiacGT]

I'd see whether the current tyres bed in first. Then possibly consider new tyres. Spacers shouldn't affecting handling that much.

[sustrafics]

Originally Posted by ManiacGT

I'd see whether the current tyres bed in first. Then possibly consider new tyres. Spacers shouldn't affecting handling that much.

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?

[jparnes1]

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?

Total BS. Everyone (practically) is switching to non-RFT and your problem is unique.

[Alext]

I have just switched to Michelin PSS and gone +10 wider on front and rear on stock rims. I do not feel any swaying. The car feels more planted at speed if anything.

The sidewalls are not as rigid as the RFTs so it has a softer feel to the steering off centre especially at lower speeds BUT at speed the response is still impressive.

[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

[rking117]

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