FLYCT

I hope you get it resolved. Please keep us informed.

Just as a point of reference, My lexus dealer recommended Michelin Pilot A/S run flats for my SC430 if I wanted to stay with run flats. They said they ride almost as nice as non-run flats.

JR

Lex07

The large and successful Lexus dealership (where I get all my work done since I have the extended warranty policy for another 18 months) said they have never switched out run-flats for non run-flats on an SC430...hard to fathom that since I called the dealer across town and they do it all the time....just shocked at the odd handling and loose steering since I switched...they also did an alignment when the tires were changed out. Today the tire guy drove it with me in the car and says it feels fine to him...BUT he rarely drives SC430's, he also said when I asked him....I am worried I will have to start all over again and wonder what I can do with 4 nearly brand new Michelin Pilot Super Sports 245/40 R18...that is the right size for the 2007, right?? ...today the service advisor said I could put them on craigslist if I wanted to go back to run-flats...lots of money for such a frustrating result....and don't understand the dealership not knowing anything about this.....

KBALL

Possible they may have over inflated tires. Start there. Measure them cold. Should probably be 32-34PSI. If youre up around 40, the car wont track as well. Good luck. If you are near a costco, they will check it and put it at what you request.

whitels

Lex07,
Odd handling, wobbly and loose steering have more to do with underinflation than overinflation. In fact, autocrossers put max tire pressure at the tracks to get the best response from tires. Make sure first the tires are inflated correctly. I have 38 in front and 36 in rear. In your case, experiment. Start out higher and then lower it to a point where you'll feel happy with. The higher psi will compensate somehow for sidewall stiffness you lost from switching out the RFTs.

FLYCT

If tire pressure does not resolve your problem and you want to go to run flats the Pilot A/S ZP run flats sell for $29 each more than the Super Sports. Call Michelin and see if they will pay to swap them out.

JR

townsville

Dear Lex07, As an ex tyre ( sorry, I am from Australia) tire fitter, I think you have made the right choice with the Michelin non-run flats. This forum has any number of sc430 owners who have made the switch and haven't looked back. Michelin is a quality tyre.

The last few thread are spot on about tire pressure. When I bought my sc430, I found the tire pressures to be way over the top. It affected the handling. Your pressures might be over or under (I suspect under). Buy yourself a quality tire pressure guage and check the pressure when the tires are dead cold. I recently bought a guage from the US for my dear father and a quality guage is well worth the money.

In terms of pressures, 38(or 36) in the front and 36 in the rear is good advice. For wheel alignment, find a professional aligner who can provide the before and after (factory) measurements. If it doesn't feel right, it can be fixed. keep us posted

mandyfig

The recommended tire pressure on our car (based on the tag) is 33 psi, RFT. What is the official psi on non-RFT?

Lex07

ALL of you have been awesome in helping give me direction since my new service advisor at Lexus seemed so clueless. He recommended selling my new tires on craiglist if I was unhappy with them and quoted me a good price on going back to Dunlop run-flats to replace them. Because of all your suggestions (that I began to quote to him on his voicemail) he realized Michelin offers a 30 day guarantee which the dealer will honor. He also said yesterday he would have another tech check some of the things you all referred to...and then I read the posts concerning inflation pressure (I remember telling them when I picked up the car that the tires sure looked low..but was assured they were fine..) So this morning my son got a tire gauge and checked.....the tires were inflated at TWENTY-NINE psi....yes, just 29!!!! So he is airing them up at the the pressure you guys have told me to try and I bet my problem will be solved....why in the world did my Lexus advisor or the tech who drove the car when i complained not get this..maybe time to switch to a new dealership for service OR another advisor...but my gratitude to all you guys who helped me figure out the possibilities...will tell you if the pressure change solves the problem...will take it out for a spin in a few hours!!!

Lex07

Also...Since this is the PLACE for great info....since I have been told NOT to use the fix a flat and ruin the sensors IF I get a flat..what are the options on that or should I just call a tow truck, being a member of AAA and also Michelin has a three year flat fix assistance thing and will tow you if no spare is available? Would love your thoughts on this, gentlemen!!!

FLYCT

You have a couple of towing options.

One: If you have an extended warranty from Lexus they will tow you
Two: AAA
Three: Michelin will tow you.

In the unlikely event that you get a Blow Out then you will need to be towed. If you get a nail in the tire then most likely the leak will be slow and just adding air will get you to a tire shop. This can be done with an inexpensive compressor you can store in the trunk

Sewell Lexus sells a compressor with TMPS Safe leak stop for $66 with CL discount
http://lexus.sewellparts.com/accesso...2007/4343.html

It can be used just as a compressor or can be used to inject TPMS SAFE leak stop into the tire. It’s a little tricky to use. I keep one in each of my SC430s. If I get a nail that causes a slow leak I would pump it up ad drive to a tire store to get the tire repaired. If I get a blow out I would most likely call for a tow or install a spare as below.

I have a Mazda RX-8 spare tire that I throw in the trunk for trips. I bought it on eBay for $150. It’s slightly smaller than the Lexus Temps spare but weighs a lot less and fits rather well in the trunk.

JR

FLYCT

Here is the description of the Lexus Compressor kit I have:

The F-Sport Onboard Tire Repair System (OTRS) is designed to repair punctures of up to 1/4 inch diameter in the tread area of the tire. Features:
•Unique integrated tire sealant cartridge and compressor in one easy to use unit. With up to 36 PSI, the OTRS injects sealant and inflates the tire simultaneously
•Lighted pressure gauge
•Non-toxic TPMS-compliant sealant
•Powered by any 12-volt outlet in vehicle
•The storage bag is made from durable canvas with an embroidered F-Sport logo. The bag also has two wide Velcro mounting strips to help ensure the kit remains in place during normal driving
The tire repair is temporary. Though the tire will last for up to 500 miles, the intention is to allow the motorist to quickly and safely complete the repair, get back on the road, and proceed as soon as possible to an authorized tire repair facility to have the tire permanently repaired.

Lex07

Thanks for the info on the compressor and other options! My car now drives normally again...the inflation issue was the problem!!! No need to switch out my brand new tires..just needed some air...WOW!!!
Y'all are better than the techs this time for sure...and now you know I'm from Texas but a big thank you to all who helped me as I was really stumped and did not know what to do! Problem solved and new friends made!!!

FLYCT

SO TELL US HOW IT NOW RIDES COMPARED TO THE RUN FLATS. Any smoother, less jarring?

Here is one more tip.

Once you have the tire pressure where you want it you should calibrate the TPMS system so it alerts when tire pressure gets below the norm. "When the tire pressure warning system is initialized, the current tire inflation pressure is set as the pressure benchmark."

To do this is simple.

There is a button under the dash that is very hard to see. I just NOW took a picture of my 2007. You have to have your head on the floor and look up under the dash and you will see the button that is labeled SET. See my (out of focus) picture. The button is really there, trust me. My wife found mine after I swore it wasn’t there.


Then from Page 219 of your owner's manual

❒ Park the vehicle in safe place and turn off the engine.

❒ Adjust the tire inflation pressure to the specified cold tire inflation pressure level. (→P. 227) Make sure to adjust the tire pressure to the specified cold tire inflation pressure level. The tire pressure warning system will operate based on this pressure level.

❒ Turn the ignition switch to “ON” position.

❒ Press the tire pressure warning reset button for more than 3 seconds. At this time, the tire inflation pressure warning indicator flashes 3 times.

❒ Wait for a few minutes with the ignition switch “ON”, and then turn the ignition switch to “OFF” position.

JR

Harold57

Thanks Flyct, I didn't know about that feature. Gee, I've only owned my SC for 7 years now...


Good to know!

FLYCT

The TPMS set button is on my 2007 and 2008 SC. I'm not sure but i think I read that it may not be on older years

JR