Like the post says my 08 GS460 for the past year or so feels unstable at high speeds, like 80+ I used to be able to go over 100 and the car would feel rock solid going down the highway, the car does have original struts and I've asked about those and the dealer and my independent Toyota shop said none of them are leaking and it would be a waste of money to replace them, they also said all my suspension looks good, so I really don't know what to consider replacing. My car doesn't clunk over bumps or anything but there seems to be much more body roll going around curves on highway and when it's windy it feels hard to even keep it going straight. Are there any bushings I should consider replacing, I'd like to do the struts but don't want to spend $2000 if it might not fix the issue. Thanks

 

My car felt a LOT better after new front struts, but you might also want to get an alignment (preferably after the struts) to be sure your wheels aren't pointing outwards from each other causing wander.

 

May seem a silly answer but your tyre pressures are correct and your tread not worn
Just a point to check

 

Sounds like your getting old

All jokes aside, I felt a significant change in stability when changing to coilovers. It could be the springs/dampening settings are aging. Does it feel the same in Sport mode? (I assume the 460s are like the 430s with the electronic dampening).

 

I keep it in sport mode and power mode all the time, but I really don't notice any difference between sport and normal so maybe the shocks aren't working like they should, not sure how big the difference was when new. I've always heard if a shock isn't leaking it's still good but I think I may replace the fronts and see if that makes a difference and if so do the rears as well

 

What tires are you running?

 

Michelin pilot sport A/S 3+ I've always used them on this car.

 

The reason I ask is because I just installed a set of DWS06 (coming from Pilot Sport A/S Plus, not the 3+) and I have the same wandering feeling at speed on the highway. 2006 GS430

 

Could be your problem. Although they're not the +, I just swapped my A/S 3's out for some Super Sports, and my 460's floatyness is gone. I, too, was experiencing the exact same thing as you, but always figured it was just how these cars were; once I put the new Super Sports on, I have next to no floating at high or low speeds. The A/S 3's that I had (about 2 years old) had an issue with the rubber chunking apart, so I think these tires were just doomed from day one. Anyways, could be it!

 

my A/S 3s are chunking too. I love the feel and quietness of the tire and I do not like the sidewall softness of the Extreme Contact DWS. Not sure what to switch too now.....

 

Do you feel shaking at high speeds? You may have a bent front wheel

But the most common and easiest is tire psi, what are you set at? If your set at oem increase it by 2 psi and see how it feels.

 

Be sure to report it to Michelin so they warranty the tires. I got my whole set up Super Sports for $700 because of this. The Super Sports are hands down the better tire here, and I'd strongly suggest getting them over any other tire. This is my 3rd set of tires (stock run flats and A/S 3's before) on my 460, and can say that I definitely notice a difference. I actually just had my first road trip on them (Seattle > Portland > Seattle: roughly 350 miles) this weekend, and they were incredibly smooth, and again, the floating was nonexistent. Only downside is that they are rated for 30,000 miles vs. the A/S 3's 45,000 (I think?); however, I only got around 26k out of the A/S3's.