Last post on Sep 18, 2013 at 7:28 AM
You are in the BMW Z4
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BMW Z4, Coupe, Convertible
#59 of 86 Re: Run flat tires [calvinc22]
Oct 01, 2009 (12:08 pm)
Calvin asked what brand of tire?
Answer: YOKOHAMA Avid 4's
Size: P225/50R16 91V
Car: BMW Z4 2004 (2.5 liter) still like new and I'm still milin and smilin.
Cost: $89 a tire from tire rack
Mounting and Balancing: $10/tire cash paid to one of the service guys at BJ's Wholesale Club. Satisfaction with putting the new tires on? Ya get what ya pay for. 2 of the 4 rims have a thin scratch because they didn't have the special "BMW" tool. But I was able to get 97% of the scratch off with a magic eraser pad and some heavy elbow grease.
Satisfaction with the Tires: AWESOME!!!!
I've got 38,000 miles on these tires now. I rotated them after 30,000 miles and they still grip great and have plenty of tread left. Okay, the back tires do cut loose a tad more than when new if I tromp on it on wet roads from a stop light. Apart from that, I really think I'm going to get close to 60,000 miles off these and no complaints. I can't imagine a better tire for the long haul and all season too. Price, Value, Performance - unsurpassed by any other.
#60 of 86 Twitchy, Jumpy Steering--'07 Z4 Roadster
Feb 13, 2010 (6:58 pm)
I bought a new '07 Z4 from a Denver dealer in July 2007. At about 3,000 miles, the dealer aligned the front-end. After that, the steering was sensitive to every bump, bulge or break in the road. Smooth roads at highway speeds were fine. But when driving in town between 25 and 50 mph the car was hard to handle.
On a crowned road, the steering pulls "downhill". If I hit a bump or pothole, the steering abruptly pulls to one side then the other. If there is a seam that runs parallel to the direction of travel, the wheels grab onto the seam. The steering feels jittery, twitchy and unpredictable. It's impossible to drive in town without worrying that the car may lurch into a curb or a hit parked car. So I drive with a "death grip" on the wheel.
I took the Z4 back to the dealer 4 times in 18 months, each time expecting the problem to be fixed. First the alignment was re-adjusted (apparently it was incorrectly aligned to M-model specs). On later service appointments, the alignment was checked again. Tire pressures checked. Nothing helped.
Frustrated, I took my car to an independent BMW garage. After a test drive, the shop owner confirmed the problem. He asked if the run-flat performance-rated tires (Bridgestone RFT (225/45 R17 front, 245/40 R17 rear) had ever been evaluated as a possible cause. To my knowledge, "no".
So I took the car to a second Denver BMW dealer. After hearing my concerns, the service manager said he thought the tires were causing the problem. So he swapped tires with another Z4 on the lot. After the swap, my car drove normally once again. Oh, happy day!!! But he had to swap them back. So I drove home with a jumpy car.
Now I'm headed back to the original dealer to see if I can get them to replace the tires. I think I'm entitled to new ones. The original set was covered for defects by a $750 tire policy I bought when I took delivery. The dealer may try to weasel out of that. Plus I don't know what to do about Run-Flat Tires. Does anyone have enough experience with this issue to know that RFT's are (or are not) part of the problem. Or is it the "performance" design of the tire? Or is it because they are Bridgestone tires? Or is it just a bad set of tires?
I would appreciate any advice, especially on how to get the dealer to "man-up" and take responsibility for replacing all four tires. I want to feel safe on the road and with spring just around the corner (maybe) I want to enjoy the ride again!
#61 of 86 Re: Twitchy, Jumpy Steering--'07 Z4 Roadster [steveclemens]
Feb 15, 2010 (11:23 am)
Twitchiness of the Z4 is built into the design. It is an unfortunate con to the tilt of the front wheels when you turn. The pro is that you can take tight corners at higher speeds. The con is that the car quickly pulls left or right when you get close to ridges or ruts. Once used to it, it's no big deal.
I think the issue is made worse with the run flats. Run flats let you feel the road surface more, every bump, every pull and ridge. Its all trade offs. I have 50,000 miles now on my Yokohama's AVID 4 all season radials. They grip better than ever on clean dry roads, there's still an 1/4 inch tread left - but I can't take the car out if its snowing - I mean at all. It was fine up until about 40,000 miles, but no snow/ice handling at all now. I'm trying to get them to stretch to May. I hate getting tires more often than once every 2 years - but then at $500 for a set of 4 mounted and balanced - I have no complaints.
I've got 80,000 miles on my 04 Z4 and have yet to need an alignment. I've hit some pretty bad pot holes and a curb once - but this car rides true and straight without pull or side wall wear. I think the car is a marvel of engineering perfection. Only the ridge affect is all I've noticed and it is minor since I dropped the run flats.
#62 of 86 Re: Twitchy, Jumpy Steering--'07 Z4 Roadster [markwell]
Feb 15, 2010 (11:57 am)
Thanks for sharing your views about my steering problem. In almost every other respect, I love my Z4. However I've had more than my share of problems. I'm on my third manual transmission--the first two frequently got so stuck in 6th gear I had to pull over, stop and use both hands to get the transmission into neutral! I'm also on my second radio--the first one would light up but no sound would come forth.
I wish I could agree with you about the steering. But I'd rather have predictable steering than a car that tramlines with every defect in the road. As far as I'm concerned, this is a serious safety issue. If I can't get it resolved fairly soon with new tires, this baby is going bye-bye! Why would I want to take tight corners at high speed if I end up hitting the curb or another car!
#63 of 86 A Smoother Ride?
May 12, 2010 (2:44 pm)
I just joined this forum on the advice of a friend who owns an import repair shop. I purchased a 2005 Z-4 (probably the last "boy toy" my wife will let me have) and I just love it!!! It has every option available for this year to include the premium sport package. It rides firmer than I am accustomed-not like say; a TR-6 I had some time ago. Yes, I am a senior citizen (South of 64 yrs.) so, the question becomes what can I replace the original RFT's with to increase ride comfort to the maximum? My Z-4 has about 40k + miles and the only thing my guy tells me after he went through it before I bought it is: oil change, possibly some brake work, rotate/balance tires. All of this: "sometime this year." The tires look very good but I am told after a certain amount of time, one should consider replacement. What is available, run flat or other wise, that I should consider to get the smoothest ride?
#64 of 86 Re: A Smoother Ride? [cliff23]
May 12, 2010 (3:35 pm)
I asked a lot of questions and did a bunch of reading over a 6-month period because I could not get answers from BMW. I finally replaced the OEM tires with the same brand/model but in a newer design about a month ago. My Z4 runs a little smoother but it still does not handle the gaps and seams in the road as easily as I would like. OEM tires were Bridgestone Potenza 225/45 R17. The new tires are exactly the same except they're Generation II. BMW is putting Gen III tires on the new Z4's but said they were unable to get those shipped to the dealership yet as replacements. That may change by summer.
In the meantime, you may want to consider a non-runflat tire option. One tire dealer recommended that route if I wanted a really smooth ride. The downside is that you need to carry a can of tire inflator plus some sealant or "slime" to enable you to get to a repair shop in the event of a flat.
If you'd like, I'd be happy to share the full text of an article by an auto writer about testing runflat tires on BMW's. It's pretty interesting background and provides a glimpse of the future of runflat tires.
Let me know if I can be of more help!
#65 of 86 Re: A Smoother Ride? [steveclemens]
May 13, 2010 (5:09 pm)
Thanks Steve. I appreciate your prompt response. Of course I would be interested in you forwarding any info you have: (cliftonburrisatt.net). After your comments, I checked my tires and they are; Bridgestone Pontenza 225/40 R18, 88W. It seems from your comments I also conclude that the "seams and gaps" are less than to be desired. I also attribute this to a minor difference between hydraualic as opposed to electric operated steering. Suffice to say, I am a person who loves to drive this car when it can be done safely--not at my expense or others. These times are rare in my area.
May 14, 2010 (7:38 am)
I assume from your note that you have hydraulic steering on your '06 Z4, is that correct? The electronic steering on my '07 Z4 may be a contributing factor to the tramlining I experience. BMW seems to be going electronic on many components to provide more feedback to the driver and more precise control. But as a real amateur about these things, that may also mean more feedback than I really want.
In response to my handling concerns, the dealer performed several alignment checks & adjustments. They also re-calibrated something called the steering angle sensor. Apparently this is another electronic device that constantly monitors the direction in which the front wheels are pointing. Again more feedback to the steering wheel.
I will send you a copy of the 3G runflat article directly to your email address along with a couple of additional comments so we can avoid doing all this sign-in stuff.
Have fun with your new toy, especially now that spring is here--at least it's supposed to be. We had a good shot of snow here in Denver two days ago but it may finally warm up enough this weekend to get our tomato plants in the ground!
#67 of 86 Re: RunFlat Tire Info [steveclemens]
May 26, 2010 (1:39 pm)
If you don't mind, I'd very much appreciate getting a copy of that article as well. Please send it to curethebluesaol.com. Thanks!
#68 of 86 Re: RunFlat Tire Info [steveclemens]
by Claire@Edmunds HOST
May 26, 2010 (3:39 pm)
It would be great if you could share the info right here in the forums too -- I'm guessing a lot of people would be interested.
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