UGAALF

I recently purchased a low mileage 2002 SC 430. The steering will starts vibrating at about 65 MPH, and it lessens, or even quits vibrating at about 80. I am not sure if it is the tires needing balancing, or the current set of tires not being particularly good. I think the tire brand is Rotalla, or something very similar. I would like, when it is time to put a new set of tires on the car, to get some non run flat tires (I am not sure whether the current set are run flats or not), as I read on this forum that the ride is much better on non run flats. However, I do not have a spare in the trunk. Are the small, temporary spares easy to come by? Does Lexus sell them and how much? Is there any other alternative to consider as I do not particularly want to get a flat when driving in the country without a spare.

Thanks in advance

Prasha

I also have 2002 non runflats, My steering will start vibrating at about 55 MPH, and it lessens and quits vibrating at about 70.. Tire balancing does not help, done many times

UGAALF

Dont like the sound of that. Do you have a spare tire, since you have non run flats?

416tt

iTrader: (1)

run flats apparently warp/bend the rim. It happened to my m3 with run flats, which I also think is the case with my SC's stocks since I have regular tires on now and there was still a shake with them.

I also find that the recommened tire size 245/40/18 by lexus is wrong as the wheel is 8" (203.2mm) wide and 245 mm is 41.8 mm wider which dont only create alot of noise but direct the wheels with the angles of the road and also make it harder to turn steering as your pushing against a sharp edge rather then rounded. (pic below).. so my new 20" inch wheels with tires only 10 mm wider then wheel in front and exact same width as wheel in rear are very quiet, very smooth, car drives very properly and does not pull me places and the bushings just make the loose feeling go away from everywhere and make allignment perfect so the car pretty much handles 100x better!!



I dont have a spare :/ just an air pump.. but my recommendation would be to get wheels checked if there bent, or try rotating them and then go with regular tires but with less width, atleast 225... I wouldnt go more on the stocks. I know many people may argue this saying lexus recommended the size. Well lexus also recommended runflats which ruin your wheels ..then wider tires just to increase comfort while they ruin suspension parts which together ruin the driving experience.

Let us know if you try anything and how it goes

OBP

Hi OP, just do a search on both topics: runflats vs regular tires and vibration at 60-65 mph. Lots of good info here. Short answer is your situation is common, you can switch to regular tires and the ride will improve, you can buy a Lexus spare tire kit ( or Mazda RX7 spare ), and you can deal with the mysterious vibration by regular tire rotation. The last solution is what I have used with some success running Conti DWS non RFTs.

Clem350

Had that problem too of not having a spare , did want to travel too far in fear of a tire going out me . Ride quality improves minus the run flats




2002 SC430.
2008 ES350

UGAALF

All this information is very helpful and I appreciate the responses. A few more questions;

Is anyone familiar with Rotalla tires and their reputation? I have never heard of them, but that is what is on my car. How can you tell if they are run flats or not, I do not see anything on the tire that indicates that they are?

I understand that all SC 430s come with the complete tire changing kit, and mind does have all of the tools under the covering in the trunk. However, I do not have the spare tire, and I see the term spare tire kit used, and I assume the kit includes the jack and other tire changing tools, is that a correct assumption? If so, can you just buy the spare tire and not the entire kit? There is a slot under the board in the trunk that would appear to be where to place the tire, however unless the tire is super tiny it seems you could not replace the board and cover with the carpet because the tire would be too large to fit underneath. Is that correct? Any help would be appreciated.

KBALL

Tire would say RFT or ZP on it somewhere.

MadHungari

Welcome to the forum. Everything (and then some) one would ever want to know about this topic can be easily accessed by clicking on the "Search" link in the center of the blue bar that runs across the page near its top. Then go to Advanced Search, enter your search term, and limit your search to this (SC430) forum. "Spare Tire" would be a good search term with which to start. I hope this is helpful.

MDames2

iTrader: (1)

If you get the Lexus spare tire kit, the trunk configuration is changed. The kit includes the new items to reconfigure the trunk area so the spare tire fits. I purchased this for my wife's 2003 several years ago. It's pricey, but it fit's perfectly since it's made for the car. It takes about 45 minutes to an hour to install the kit, including the spare tire. Great peace of mind for me knowing that my wife won't be stranded in case of a flat.

Autoplak

Great idea bimmer416, as a question of tire size of 245/40/18 is probably Lexus recommended for the OEM RFT, however, one could wonder if it is the same for non RFTs.
To bimmer, are you running 18 or 20" on your SC430? Does the 225/40 have a speedometer error? I did a tirerack search and the 225/40 does 831 RPM and the 245/40 does 806 RPM. I'm not that knowledgeable if that is a significant difference noticeable on the speedometer.