I am sorry to read this.

As frustrating as it is (and believe me, I understand; I feel every vibration/imbalance, and thus have encountered and fought these "battles" many times in the past), you should consider pursuing this further if you can.

RFV of 28 is not good (and on my LS460, a slightly lower number definitely triggered a vibration that only I could feel, but the machine confirmed it). However, if the shop hasn't fully utilized the capabilities of the GSP9700 road force balancer to match tires to wheels and optimally mount them, they should, as I'd be willing to bet that this number could be made much better. This has, FWIW, been my experience in the past. Will the 28 become 3 or 4? I doubt it. Could it be brought down to the teens? Probably.

Since we are both in MA, I am happy to help in any way I can with a referral, etc. I've been down this road before (no pun intended) and have met folks who truly take advantage of the machine's functionality and others who barely know how to use it.

Lastly... While the unofficial limit for the LS is 10 lbs, the limit "out of the box" for passenger car tires on the GSP9700 is set to 25 lbs. As such, absent a better mounting location for this tire, it fails even the less strict requirement, making it a clear candidate for replacement (subject to how "with the times" your installer is).


No comment on the Continentals... This is exactly my experience. Ditto for the shi**y Falken summer tires that the selling dealership put on my 600... because that makes sense

 

Appreciate the help guys. I am not questioning their ability to work the machine as the one was a 5, the other an 8 or 9 (I forget) and the other was around a 15. So I would think if something was up with them either not setting the machine up right they wouldn't have been able to get the other numbers so low. Also they were able to set one of the Continentals on with a really low number as well.

I am beginning to question a possible control arm issue? I've looked at them briefly but never noticed anything wrong. I did recently do all 4 brakes. Tomorrow I plan on checking the brakes to make sure everything is good there. Now that I think about it, I do sometimes feel a slight shudder when accelerating from a dead stop. I can feel it coming from the front left area. Not sure if a bad control arm bushing would present itself at 70-80 mph but until I get all these tires correct, I can't rule anything else out.

 

Are they certain its the tire and not the wheel? Your LS has a matching spare tire and wheel, try mounting it on there and RFB and see if the RFV is still that high...

Control arms wouldn't affect the RFV...

 

Good idea. Never thought of that...

 

Keep in mind that RFV is a function of tire AND wheel (as Steve alluded to). Tires are never perfectly/uniformly round (geometrically or in terms of stiffness around the circumference). Wheels are not perfect either, and the machine relies on matching imperfect tires with imperfect wheels to achieve the "roundest" combination.

True, you could include the spare wheel in the mix for testing purposes, but that should not be necessary. My point is that when tires are done as a set, each wheel is measured individually by the machine, and the machine will recommend to the technician which wheel to put a "problem" tire on. To the extent your tech did that, you have a bad tire. If he didn't, the fact that other tires are so low doesn't mean much more than those tires "worked better out of the box", so to speak. Of course, when this happens (3 of 4), chances are that 4th tire is not as uniform as the other 3, irrespective of wheel. But again, that's where the machine, when used to its full potential, shines.