Spent the morning at the dealer...he infomed me that most cayennes that have 20's and 22's have vibration problems....combination of the tires wheels etc.....even all stock

He mentioned that Pirelli have the most problems...michelin the least....each tire and wheel has to be perfectly matched and they havea special machine that even tells them where to position the tires on the car to help smoothen out the ride...can i get some opinions on tires from those running 20's and 22's as they will be changing my tires..i am currently on the continental cross contacts....thanks in advance

 

Sorry to hear.. Road Force.. Search term here and on roadfly.org -- it applies to all tires.. this vehicle appears to have a propensity to send a shimmy-vibration that you can feel between 50-80 mph (depending on tire RF etc.). On these bigger tires with more $$$, I'd insist on low RF numbers .. In the teens or lower.. Hunter Machine to determine factory spec. RF number and then don't accept any with high RF numbers. Again, read other posts.. it is likely your dealer has read these posts..

 

what is low what is high RF number? can you tell me what is acceptable? Dealer insisted that with 25k and new set of wheels and tires that I do a $380 wheel alignment as it is time to do it.
Road force balancing will be $120.

 

If you are on your first set of tires and made 25K that is pretty much the high water mark for Cayennes. Look at all the posts on roadfly and search the term on yahoo/google... to get a more technical explanation.

Basically from this forum and roadfly postings.. it is my belief that the cayenne's tight manufacturing, weight, AWD, harmonics etc. add up to a shimmy/vibration if a tire is "out of perfection" by a Road Force number much above 15 or so. Tire manufacturers say you can use a tire with Road Force as high as 30 or 35.. BS! Michelin has a patent on the design of their wheels and it appears to make them closer to perfectly round and thus have lower RF numbers. I posted my Michelin Diamari RF numbers... one was actually a 0 technically perfect (with the tolerance of the machine being able to tell) and the rest were all under 10.. after bridgestones (RF teens to 20's) and continentals (all RF in 20's) --- ALWAYS had shimmy/vibration at 65-75 to varying degrees (depending on alignment/balance etc.) I am TOTALLY shimmy vibration free. I have 18" wheels BTW and am not hyper about the look of the wheels (i.e. 20-22). Road Force is very Important for the ride of the Cayenne.

Yes, I paid for the alignment each time I got new tires.. definitely recommend.

 

thanks for all the info...wheel alignements at local garages are around $60-$70 however i recommend a pro to hande the job and the gooing rate i heard is around $120-$150....not $300.....again thanks for all the info....i will make sure the roadforce is in the teens...one other thing...i have what is called a jump in my wheel...even though it balance oerfectly....you can see it is not perfectly round....any suggestions on this? thanks again

 

Here are what I found out on my own experiments. I had 20" sports design with continental. My steering wheel was vibrating all the time. I went to different dealerships and hope to have the problem solve. Even one of the dealer did road force balance for me. But at the end, problem was still there. About 8k miles (all tires were about done), I bought a new set of sport techno (20") with Pirelli. The first thing that I notice after I put the new wheel set on was the vibration was gone. No more vibration, I am so happy about it. I even bought another new set of Pirelli to replace the Continental set on original sports design. My next door neighbor also has sports techno (because of him, I bought a set of techno) with Michelin. His Cayenne has vibration all the time and the problem never solve. Recently, I put after market tire pressure monitors on my Techno wheels. The vibration came back. I went back to the shop (I know the owner of the shop) 2 times to solve the problem. I even planed to give up on the 3rd try. But we had them balanced on the 2nd try. We did it without road force balance, but we did use 2 balance machines. What we found at the 1st shop visit (after the TPM was installed) was the balance of 2 front wheels were gone and rears were OK. The 2nd visit we only checked the front wheels and their balances were gone again. This time I ask them to use 2 balance machines to see if the problem is on the calibarition of the balance machines. The reading of the 2 machines were differnt. We switched the wheels back and force to check the consistency(weight difference and position). We made sure that they were consistent. Then took off all the weights and balanced the wheels again. Problem solve.

 

all i can say is wow!!

 

Maybe this is why Porche has a wheel and tire guide of their own. Do owners that use Porsche Cayenne wheels have any of these problems? Just curious. JW3

 

all I can say is ROAD FORCE.

Mav's description points to the fact that he just had someone work really hard to counter-act the tire's inherent "out of round" and imbalance by having a tech use two non-hunter machines and spending a HUGE chunk of time to get it compensated for. As soon as you hit a big pothole or rotate the tires or in his case add PSI sensors.. back to the SOS.

IMO and others, the problem with the Cayenne is that the drivetrain/steering wheel/tire combination apparently magnifies the imperfections of the tire (i.e. balance to manf. defects). Understand this... Road Force is the pounds of force that a wheel is out of round from the manf. process (when it is final assembled by a variety of methods - Michelin has a patent and does it in quarters.. most assemble in two halves). Tire manufacturers have a spec'd maximum that is much higher than what this SUV can handle from a vibration standpoint..... thus, I will not buy tires that have RF of anything greater than a RF of 10-15 --- PERIOD. Again, broken record here. Read the technical jargon and info on this forum and roadfly.org (cayenne) by searching on the term: road force or shimmy or vibration or hey all three (and google it too).

GOOD LUCK.

 

thanks for all the info....my cayenne is at the dealer...have a cayenne loaner with stock 18's on it...i feel a very very slight vibration...same type i have on mine with the 20's..but because there is more rubber on the road not as apparent...i am convinced now that the cayenne does not have the right type of sterring mechanism or power steering or whatever that is actually called....if i cannot get this straightened out by going to the michelins and all these road force tests...i will write a letter to Porsche in germany....would any of you be willing to provide me with your VIN numbers names addresses etc and i will have a professional letter drafted and sent to Porsche..... representing a group will have more power....anyone want to be part of this? If i get a positive repsonse i will post a thread covering this...you think this is a good idea?

Feedback would be great....thanks

 

In my case, the issue is now resolved, so wouldn't participate. Many/most Cayenne owners do NOT have the problem or don't notice it. Thus, I think Porsche would nicely say "Sorry". I truly believe you can eliminate it in your SUV with low RF tires and proper alignment/balance. Again, read the "road force" technical explanations from a google/yahoo search. Lastly, if you have low RF tires (<10) and you still have the vibration, you may have a cardan shaft issue (also spelled in posts as carden)... this was an early run issue that I've not seen discussed in over 18 months but again do some forum searches on that and you'll know if that is the case as well. Good Luck.

 

exactly. I could balance 20's by my hand feel, stick them on a '79 Blazer and there would be no shim. It is rediculous that perfect tires are required from a RF standpoint. There is a fuse for servotronic that I plan on pulling and see what happens. Servotronic is responsible for determining how much power steering assist is given at a certain speed range. The faster you go, the less power is added to the steering. I will report my findings...ie warning lights, not driveable, ect...This issue pisses me off. Some days like today on my work commute no vib at 72 mph. The day before it did. Mine ranges on my 20's Sport design with Michelin's anywhere from 68mph up to 75. There is no consistancy...

 

A positive response? Would you settle for no response?
PAG, once they stop laughing, will merely forward the letter, if you're lucky, to PCNA.

 

For what its worth since 9k I have had NO vibration at any speed <135.

I put it down to the dealer learning how to set it up right.

On 18's tho'

 

I have read many posts about the same wheel vibration many times.....plus ever since i posted a few threads about this i have communicated with many members...even ended up with a fellow montrealer with the exact same problem who coincidenatlly bought his tires from the same shop...bought his car from the same dealer and has the exact same problem....the head tech at the dealer told me almost every customer with 20's and above has complained about the problem and they spend hours on each car to find the perfect combination...this cant be right.....plus every time they give me a loaner...with 18s stock i feel the same thing just not magnified as much as with 20's.....just got back home still have the loaner and still the same thing....this cant be right for sure.....anyway...i hope i get this resolved but definitely not something i expected from a porsche...my 996 has a more stable feel.....cheers!