Hi Guys,

I have an 08 GS350 AWD which I really like. However, two things have been driving me crazy; Rattles and the ride comfort is not great (road noise, bouncy/jarring over road bumps and the like).

I will tend to the rattles once the weather warms a bit. For the ride comfort, I am trying an experiment with the tires:

1-The Dunlops that came the car are junk. User ratings on Tire Rack trash the tires, especially for road noise and ride quality. I concur.

I will be going to the General Altimax, which I have experience with. Good tire, quiet and comfy ride. Good value too.

2-Change the tire size to 215/55/17. Larger aspect ratio, more sidewall. Should work, based on what I have read.

I will let you know what I experience. The tires go on tomorrow.

Wish me luck.

 

Guess I am in the minority but I miss the oem Dunlops. Yeah they were noisy and not that smooth but still miss them when cornering and pushing the car a bit.
I just replaced the Dunlops with the Pirelli P Zero All-Seasons and plan to go back to the Dunlops after I go through these at least halfway.
Good luck with ur experiment. Let us kmnow here how it goes.

 

Given the age of my car, I am not sure these Dunlops are the OEM brand. Likely, the cheapest tire they make?

 

Let us know how much the tires made a difference. Changing ur shocks too will help bring back that original solid ride

 

I'm with brucelee1 on this one..
Please let us know what you discover with the new tires..
I've put on about 2000 miles on Michelins A/S Sport 3+ and not certain these are the best tires for this car.

 

Going from any "junk" tire to a new tire will make a tremendous difference no matter if you go to a 50$ tire or a 250$ tire. The Altimax is a great tire because it's a touring tire which will help absorb a lot of the road noise and imperfections.

I wouldn't consider the 215 55 be a larger aspect ratio than stock. It's practically the same and that difference if any, will not transfer to absorbing the road a lot more. If I had to take a guess, maybe 1/4 of an inch difference which is barely noticeable. You should be looking at 225 55 if you want a better aspect ratio that can help absorb some road imperfections; granted if they fit.

 

Not sure. The aspect ratio (50 vs 55) is different so, it should make difference, even if just a little.

 

This is going to be fun. I am hopeful of an improvement, but I am willing to report disappointment. Hope not, as I really want to keep the car.

 

I have Toyo Luxury Touring and major road noise.

 

Aspect ratio represents the percentage of the width. It is NOT an actual number you base the tire height off of. The height of 225 50 vs 235 50 vs 245 50 vs 255 50 is NOT the same. 50% of of 235 will obviously be taller; 50% of 245 will be a lot more taller obvious, and so on.

You're going with a smaller width but a higher aspect ratio which in affect is very similar to 225 50 to start. If you want to be very technical, yes 215 55 17 on paper is taller, but by 0.226378 inches. Air pressure affects the tire height where it contacts the road and absorb imperfections more than that.

Anyways, good luck; they are going to ride much better because they're new tires. But the tire is not the sole issue of rattles, ride comfort, road noise, bouncy/jarring over road bumps, and the like.

 

According to the calculator, you are not correct. Additionally, I have observed that the tire is taller (standing next to the existing tire) and 10MM narrower. We will see, which is why we call it an experiment!

On your last point, I am not expecting the world, just an improvement. And yes, the rattles will have to be dealt with later in the Spring.
Thanks.

 

Tire pressure was mentioned..
I decided to run some tire pressure tests on my new Michelin's .. Using Techstream/Live Data/TPMS what I discovered was 33.0 (recommended pressure) was not ideal tire pressure and in fact much too high. I believe Lexus changed their tire pressure recommendations to improve MPH.
I dropped to 30.0 (on the TPMS), too low, the ride was "mushy" and while on rough roads there was clearly no damping.
I went up in increments of a half pound until I found the sweet spot (which, by the way a half pound change in tire pressure was substantially noticeable). The ideal pressure seem to be right at 31 PSI @ 70 F. on TPMS/Techstream. This calculated to 29.5 on a digital pressure gauge (most, if not all store bought gauges are off approx. 3 LBS).

 

Thanks, that is great information. I will try that experiment as well.

 

Well, so far it is clear the tires are much quieter than the old Dunlops. I also think the ride is better, but it is hard to tell just yet. As far as the rattles go, I am noticing more every day. Arghhhhhhhhhh, I love the car, but I may be back in an ES350 within a month or so.

 

Man, I wish I knew what the dealership did to my car to make it not rattle, when I looked at the service history I saw it was brought in twice when it was young for rattles, and my car never has rattled the entire time I've owned it, even in sub zero temps. There must be a Lexus tech who's figured out how to fix it. Have you tried the fix that's on the forum?