pmarsh22

On the day I bought my car, I asked the sales guy, what tyres ??, his reply "don't worry, they are'nt runflats ?? it has normal Dunlop's"

I have since replaced x 4 with Eagle F1's, they are brilliant and make such a difference, especially in the wet.

1NICESC430

Yes, pmarsh22, those F1's are great on both dry and wet roads.

Initially F1's are relatively quiet, but if they become unevenly worn they become unbearably noisy (as mine are). Rotate them every 3,000 miles and make sure your car is always properly aligned to avoid the torment. Fortunately, the difference between what I sold my runflats for and what I paid for the F1's was only $25 a tire so I don't mind dumping them after only 9,000 miles.

I'll be replacing them with Bridgestone Potenza RE050A Pole Position tires. While they are asymmetrical, they're not directional so they can be rotated front-to-back *and* side-to-side without dismounting them from the wheels.

Good luck with your F1's.

KevsSC

Do you guys think that if I change to Non Runflat tires, I wont bottom out as much? I have Tein CS and I want to lower the coils all the way. I did this before and I started bottoming out on every small pot holl and crack. Any advice? Teins said that maybee the bump stop is not cut in half. I still have to check that. I currently have Runflats and I dont like them. The tires are still good so I dont want to junk them yet. But if it will solve my bottoming out problem then I will switch.

tfischer

I'm no tire expert but I don't think that changing the tires would fix a bottoming out problem.

As I understand the term, bottoming out is mostly a factor of the shocks and other suspension components. The only way a tire change would have much effect would be if it were a high profile tire and you were changing from a very rigid sidewall to a softer sidewall; in that case the tire itself would absorb some of the shock and the suspension travel would be less.

However, the tires on the SC are pretty low profile already, and although the standard tires are softer, because the runflat has, by definition, a very rigid sidewall, I would not think that the difference in vertical movement over an obstruction would be enough to make much of a measurable difference.

Besides, bottoming out is not a common problem reported here, and if that were caused by runflat tires, I think there would be more posts on the subject.

KevsSC

I didnt think changing the tires would resolve the bottoming out issue. Thanks for the input!

rominl

iTrader: (4)

it won't affect anything. you just change the tires, as long as the tires are the same profile, it's the same thing

zgxl04

My run-flats have about 1.5K miles on them. A couple of weeks ago the low tire pressure sensor came on so I checked the tire pressures. One of them was down to 12 psi. I inflated that tire to 45 psi and drove it for a couple of hours and the car was parked for the rest of the week. Next weekend the same thing happened and the tire pressure is down to 18 psi. Can this run-flat be repaired or is it toast? Somebody had a posting a while back about losing tire pressure but I couldn't find it any longer.

tfischer

You will have to take it to a tire place that is experienced with run-flats. I understand that they are unusually tricky to take off the rims, and not every tire dealer has the tools and experience for them. Also, you have tire pressure sensors in there that are also somewhat unusual.

For these reasons, you Lexus dealer might be the best place.

First you need to find out why the air is leaking. I hear that a lot of leaks cannot be repaired, but that some can. If the problem is with the stem, you might be able to get that fixed. At 1,500 miles, that could well be a stem or an installation problem, and there might be a warranty on the tires that would kick in.

A slow leak could be anything, including a nail.

Good luck.

Samanator

Since I recently switched from an Audi TT to the SC I think everyone here is being a little harsh on the runflats. Even over railroad tracks I don't seem to feel that they are all that bad. We also have a is250 that we bought this year and that car is said to be harsh (according to the auto mags). I guess after several German cars over the years even these rough riding Lexus feel like clouds. Mine is a 2007 SC so maybe Dunlop improved the construction.