2006 Gs Rough Ride

[Richen]

Just went to BMW test drive X3 and 325xit this morning. Both car rides are smoother than my current GS. The ride is solid on both BMW. I am about to pull the trigger.

[SW03ES]

Personally, I'd try and get to the bottom of what is causing the issue before I took a total bath on the depreciation on the Lexus.

[Richen]

SW03ES,

Thanks for the advice. It I will go to dealer for one last time to see if they can find any problem. This car doesn't ride right. Unlike most of the owners who seems to enjoy there car.

[SW03ES]

Are there any more dealers in your area?

[Richen]

I went to another dealer two weeks ago. After test drive by the mechanic, the result is normal. I do feel the dealer doesn't want to go further because the car was not purchase from them. They are very kind though. The recommendation is to contact Lexus customer service center.

[Richen]

The local Autotech tire shop owner who recommends not invests any more money on this car. The ride character is come from Lexus build quality. There is really not much I can do if Lexus can't find any problem. He also mentioned the driver seat is too hard on GS, doesn't provide enough cushion to absorb the vibration from the road. Both BMW and Audi do a great job on the seat cushion to filter out most of the vibration. The best way now is to start test drive, find a car that I like and replace it.

[SW03ES]

Did the dealer's tech also drive another GS to compare back to back?

As for the ride quality being "because of the build quality of the Lexus" remember that Lexus is known worldwide for their smooth and quiet ride, and while the GS is firmer than the ES or LS its still a very smooth and quiet car. It sounds to me like the tire shop doesn't know what they're talking about. I've driven all the BMWs and Audis and the GS, and there's no question the suspension on the GS is a lot softer. Remember he installs tires for a living, he's not an expert on foreign automobiles.

I'm not advocating you spend more money on the car, I'm advocating you trying to get Lexus to determine if there's an issue. The only way to do that would be to get a tech to drive yours and another GS back to back and see if they can see the difference that you see.

[donbl]

I just finished a 2800 mile trip with the car turning over at 5000 miles when finished.

The ride was smooth, soft and enjoyable. I did have to pay attention as the steering is a little more responsive than I am used to.

I anticipate the soft tires will cause a rough ride starting at about 10000 miles.

Will try something a little different at 10000 miles providing a good ride but more than 10000 miles next time.

As for cornering, that should "not" be the tires but it could be the electronics.........

I have Yoko's regular tires and happy with the car and tires at 5000 miles.

[Richen]

I think the tire shop owner is talking about my car might have built quality issue not pointing at the Lexus.

Like I said, the car was smooth at its first 10,000 mile. I did enjoy the car like everybody else. After 10,000 mile everything goes downhill. I switch to regular tire at 16,000 mile, the ride is still stiff. I am not sure if it is related to the tire that I choose Michelin Pilot 225/50 "Z"R 17 A/S.

When the car was at 12,000 mile, I did ask for test drive with service manager to compare with another GS, the result was normal (the compared GS was a trade-in vehicle not a demo).

I plan to schedule another visit to the Lexus at 19,000 mile.

[donbl]

Spent some time on TireRack today searching for comments on all the tires that can be used on GS300.

Reviews by users were all over the place.

I believe the issue with rough ride is usually worn tires. And that the rough ride just starts about 10K miles.

I am not sure there is a good riding tire that lasts much longer than 15K miles.

[Richen]

Yesterday, the tire shop adjust my tire pressure to 30 psi on all 4 tires. After driving for a day, I feel no control of the car at all.

Two weeks ago when I was at Lexus dealer, I notice the differences between OE Dunlop RFT and Michelin Pilot Sport that I currently use. When the tire was new, tire wall on the Dunlop is stiffer than the Michelin; but the rubber that actually contact the road (is it called tire surface?), Dunlop is softer than the Michelin. That might explain why after I replace the tire to Michelin tire with softer compound, the handling and ride comfort does not improve, because of the improper tire pressure was used. It reminds me that Steve did recommend to air up my Michelin tire the other day. I thought 36 psi for all 4 tires is good enough.

This mooring, I air it up to 36 psi front, 38 psi rear. Magically, I feel more control of my GS. The side by side movement has reduced. Since the maximum inflation is listed at 51 psi on the tirewall, I will continue to air it up until I feel more control of the car. Couple weeks ago, I read a post said that some mechanic recommend 36 psi front and 40 psi rear on the Michelin Pilot tire. It is raining now here in New Jersey, so I will do it when the rain stop.

[Richen]

Just checked the Tire Rack user review on the Michelin Pilot Sport A/S. I found two different results from the user reviews. Some users like the tire, some don’t.

The user who dislike the tire listed: Due to its softer rubber compound, cornering and highway traction are not as good as Pilot Sport summer tire and Michelin MXV4, especially when mounted on certain cars with sensitive steering. Another user thinks it reminding him how a Camry drives.

I do agree with the description above. But, there are so many Camry out there. It just everyone has to find a right tire to fit his car.

[SW03ES]

I told ya ;)

Dunlops do have softer rubber compounds than Michelins, but the downside to that is that the Dunlops wear out a lot faster. They're cheaper though, so that may or may not be an issue for you...

[Richen]

Yap! I start to feel Dunlop tire wear in less than 10,000 mile. After that, the traction and road noise went down hill and it is decided by how you going to live with it or not.

I had a discussion with Lexus service manager this morning who advice me not to hand over the 50K car to any other party except for Lexus. Therefore, I scheduled another appointment with Lexus tomorrow morning to check if there is any problem with the suspension. The recommendation form the Lexus service manager for the replacement tire is the OE Dunlop RFT tire. It seems that Lexus will backup their tire decision. Unfortunately, customers like me have to deal with these tire issues.

[SW03ES]

Don't buy the runflats, I'd try and get a standard Dunlop tire...

[Richen]

Guess what! After air up the tires and complete 4 wheel alignments, the ride comfort, cornering and traction are improved.

Lower tire pressure will not improve ride comfort. At least Michelin doesn’t. Now I understand why Michelin made the tirewall so soft. First, you must air it up to more than 38 psi, than the tirewall will start to do its job. Without proper inflation, tirewall not only can not absorb vibrations but also reduce road traction. I feel no control at all at 30 psi.

Softer tirewall will allow the tire to absorb all kinds of vibrations comes from road. Harder tire surface means less tradeware. I'll choose to stay with current Michelin Pilot Sport A/S tire and switch to winter tire before first snow fall. I will definitely not going back to run-flats no matter what Lexus said.

Thank you guys for all your help! I am very happy now!!

p.s. I might try 40 psi on all 4 tires...

[SW03ES]

Good! I'm glad it worked out.

[Richen]

After I fill up my gas tank yesterday, I found the ride is even smoother. It tells me that I probably have to go to gas station more often. Although it might waist some gas, I might keep my clubs in the trunk. Maybe I will have extra game you never know.

[Richen]

After I air up to 40 psi on all 4 tires, both ride comfort and traction are amazingly improved. The stiffer ride is not as bad as what the tire store technician said. In fact, I feel more confidence on 40 psi compare with 30 psi tire pressure.

[Richen]

I hope the 40 psi will not create rattles when temperature dropped. That is one of the reasons why I will switch to winter tire.

[donbl]

I hope the 40 psi will not create rattles when temperature dropped. That is one of the reasons why I will switch to winter tire.

My suspension was found out of alignment at 5000 miles: camber, toe and rear. Did not hit anything as I drove most of the miles on a trip.

Interestingly, the dealer did a "free" unsolicited alignment and found the problem.

If it had not been done I am sure we would have been encountering a rough ride shortly........

[Richen]

I hope the 40 psi will not create rattles when temperature dropped. That is one of the reasons why I will switch to winter tire.

My suspension was found out of alignment at 5000 miles: camber, toe and rear. Did not hit anything as I drove most of the miles on a trip.

Interestingly, the dealer did a "free" unsolicited alignment and found the problem.

If it had not been done I am sure we would have been encountering a rough ride shortly........

donbl,

It seems to be interesting information. I just went back from dealer for 20,000 miles service. I feel not in control of my car. But the dealer tells me it is normal.

I did a 4 wheel alignment 2 weeks ago. Do 4 wheel alignment different than the suspension alignment? Did you found it or the dealer?

Thanks for your help!

[donbl]

donbl,

It seems to be interesting information. I just went back from dealer for 20,000 miles service. I feel not in control of my car. But the dealer tells me it is normal.

I did a 4 wheel alignment 2 weeks ago. Do 4 wheel alignment different than the suspension alignment? Did you found it or the dealer?

Thanks for your help!

The dealer claimed it was pulling to the left which caused him to unilaterally do an alignment. I did not notice it at all on the trip................

I am not sure of 4WD alignments however on 2WD alignments there are two forward and one aft on the alignment and all three were bad. And, not just a little bad......... glad it was caught or I would be buying tires about 5000 miles early.

[Richen]

I feel the suspension become weaker. I had to carry 2 golf bags in my trunk to maintain firm ride. The ride is harsh when I ride alone. I am not sure if 18" tire will improve my harsh ride.

donbl,

It seems to be interesting information. I just went back from dealer for 20,000 miles service. I feel not in control of my car. But the dealer tells me it is normal.

I did a 4 wheel alignment 2 weeks ago. Do 4 wheel alignment different than the suspension alignment? Did you found it or the dealer?

Thanks for your help!

The dealer claimed it was pulling to the left which caused him to unilaterally do an alignment. I did not notice it at all on the trip................

I am not sure of 4WD alignments however on 2WD alignments there are two forward and one aft on the alignment and all three were bad. And, not just a little bad......... glad it was caught or I would be buying tires about 5000 miles early.

Lucky you! My dealer told me my car is normal. I just don't understand how other GS owner could stand the harsh/ rough ride if my car is considered normal.

Good! I'm glad it worked out.

After came back from 20,000 mile service, dealers rotates the tires and adjust tire pressure to 33 psi.. I feel no control on 33 psi. Air it back to 40 psi, but the firm ride is disappear. Adjust tire pressure to 36- 40 psi plus two sets of golf bag in the trunk to keep the smoother ride. It seems my GS ride is improved during rainy days. I feel more traction and ride comfort.

[micnn]

This thread has encouraged me to experiement with the tire pressures. I recently installed a set of Turanza LS-Z on my 2002 gs300. At the end of break-in period I started playing around. I am amazed how little the change (~ 2 psi) in tire pressure can create a rather noticeable difference in both handlings and comfort. Nice going!