mike2150

I have an '07 with 20k miles. Lots of tread left on all four tires. Left front was losing about 6-8lbs/week for the past few weeks. Almost zero pressure today. Tire shop showed me that all four tires were separating on the inside of the tire. Now I need 4 new tires. Ever heard of this? Thinking of ditching run-flats for regular 245/40-18's. Thoughts?

cowsgomoo

iTrader: (2)

100% ditch them. Try and get a spare though. Runflats are heavier and louder and don't wear as well as regular passenger tires.

Stormforge

regular tires are better than the run flats, lots of members here who had run flats have ditched them. having said that, see what kind of tire warranty you have. your dealer may be able to replace them for you for free (i would think this is can be a warranty claim?). if your dealer agrees, ask them to replace with regular tires instead of run flats. good luck.

guitarmike

at 20k miles the dealer more than likely won't replace them for you. I will not be considered a warranty issue as 20k miles is well beyond the "premature wear" stage. I would, however, consider all the options for the non runflats. You will be much happier with the wear/ride, and life of the non runflat tires.

*Batman*

A lot of tires have warranty beyond 20,000 miles for construction quality though not for tread. Since your problem is not tread wear related it may be possible to make a warranty claim.

The advantages of run flats are:
1) firm side wall means car is flatter during cornering
2) much safer in event of a high speed puncture
3) ability to drive on a flat tire so you don't need a tow or to change the tire on the side of the road.

disadvantages are:
1) more likely to wear out early as you experienced
2) firmer handling and ride also means you feel bumps more and worse ride quality
3) more expensive

rominl

iTrader: (4)

umm, not sure about that. my sc430 with runflats i was less than impressive with the cornering. firmer side means nothing when the tire itself has poor traction

*Batman*

Yeah but if you had factory run flats then this would just be a consequence of having low performance tires. What I am saying is that the firmer sidewall of the Michelin PS2 run flat results in better handling but worse ride than the Michelin PS2 regular tire.

rominl

iTrader: (4)

umm interesting. are there any links or report between ps2 runflat vs normal ps2 and that the runflat has better results?

rld14

Runflats, in my experience, are nothing but aggravation. Just check the reviews at a place like tire rack, people almost universally hate them. Had my GS350 come with run flats I'd have ordered a spare tire and regular rubber the day I bought it.

On the other hand, I suppose it would be nice not having to change a spare on the side of the road...

Modeler

I dumped my runflats right away. They are a complete garbage. Riding on regular tires is a completely different experience in this car.

*Batman*

No but they are very similar except for the more rigid sidewall. With all tires a harder sidewall helps sharpen steering response in cornering. I found people on the BMW forum who have both PS2 and PS2 ZP and they also said the same thing.

Tire rack surveys also suggest a slight edge for the PS2 runflat on cornering stability, however the survey results are strikingly close.

LexFather

All sports vehicle with OEM PS2s do not have runflats. This includes Lexus own IS F.... I need to read on the PS2 with runflats, don't know much about them.

*Batman*

That may be true for Lexus but not for all OEMs. PS2 run-flats are OEM equipment with Corvette, BMW, and Audi.

rominl

iTrader: (4)

bmw? which bmw?

*Batman*

It is one of 3 or 4 OEM tires used on the BMW 335 Coupe. I think tires vary by region, but in Florida 335s mostly come with summer tires.