Nope. Four wheels with run-flat tires weigh more than five wheels with conventional tires, at least in the sizes I've inquired about. Run-flats are heavy.
TPMS & Run Flats I've had 3 separate warnings about low pressure over the past 5 years on the wife's X3, which turned out to be nails/screws/etc. in the tires. I drove them immediately--and slowly--to a nearby tire shop and got them repaired, and the tires are still fine. Love TPMS!! I just replaced the OEM Bridgestone RFTs, which had gotten downright dangerous after a couple of thousand miles, with Michelin PS2 Zero Pressures. I'd say that technology has now gotten us REALLY close to regular tires with these ZPs. I've got 350+ miles on them now on all kinds of roads (70+ hway; REALLY bad city roads [PDX], twistees in the mountains [PDX to the coast and back], REALLY hard rain, warm and sunny), and these are great tires on the Z4 Roadster. The only time they are harsh is when I've hit a really bad pothole, but the Roadster would be harsh over that anyway because its sprung so tightly. They provide the right amount of feedback for a Roadster (not for a 3er, 5er, etc., which some folks obviously think a Roadster is supposed to feel like...you know those idiots who say on some forums how they'll never buy another BMW because the Z4 they bought was too harsh, so they bought a Lexus and it feels just right to them). You know the valleys are there on the hiway, but you're not being tossed back and forth by them. They're fairly quiet and even at 350mi quite sticky. I stayed with Run Flats for safety, but these are just really good tires regardless.
Run Flats I always get flats - seemed to had flats with every set of tires. Just replaced the rear tires on my Z4 - sidewall cupping - plus a nail. I've even had side wall punctures - while driving in a paved neighborhood.
I-55 South on my way to Memphis a few weeks ago. Opened the trunk to get my spare and had to call BMW RSA for some air for it. Thank god, I was miles from anything resembling civilization.
Last time i had a flat was in my e46 325i. I was leaving home and felt the thump of a huge bolt in my tire just before i exited the neighborhood. I made it back into my garage before it was totally flat. Put the spare on in a jiffy and wasn't even late for work.
Is it karma or CARma? In 1993 I got around to buying my first car (Audi) and had a total blow-out of a rear tire at 65mph just south of Seattle. I heard the pop but felt nothing. I knew one of my tires was iffy so pulled over just to make sure it wasn't me...it was. Sold the car and bought a motorcycle. (Talk about a real problem, MC tires last all of about 6000 miles...but that's for a different forum.) Fast forward to 1997 when I resumed driving on four wheels. Over five years in AZ I had zero tire problems (but did have the windshield replaced three times ). Lived in VA for two years and had zero tire problems. Five years ago we settled in FL and between two vehicles we experienced one screw and two leaky valve stems. Then "it" happened. In December 2008 I purchased my first BMW which is also my first car with RFTs. One month later I got a nail through the sidewall and replaced the tire ($300!). Other than the cost it's not a big deal, no tire can survive a sidewall puncture. Since January 2009, my Bimmer has collectedSEVEN screws The car is now sitting in my garage with a tire full of slime while I decide what sort of tires to buy. By the way, that's a puncture every three months. In the same time period my wife, who works in an industrial area, had zero tire problems. I'm convinced RFTs are screw magnets precisely because they are not to be repaired. Coincidentally(?) it's always the front tires that find the screws, with the right side earning more than the left. I admit that I have been taking my chances by having a friend mechanic do 'unauthorized' repairs, but could you imaging paying $300 every three months for another new tire? I can't, and instead of $1200 for OEM RFTs I will be buying non-RFTs with a spare from Bavarian Autosport for less than $1K. The ability to repair is too big a cost and convenience advantage- despite claims of improved safety.
I decided to give this stuff a try... http://www.tireguardian.com/ ... Like several of you, I wanted to get rid of the RFT's for various reasons but I hated the idea of having to give up so much trunk space to a spare/jack/etc. I read about this stuff on UUC and BimmerWorld's websites and I love the concept so I thought I would give it a shot. Unlike the typical 'slime', this stuff goes in before you get the flat and is supposed to provide a permanent fix. It's had no effect on the TPMS so far and it's been about 4 months now. We'll see if it actually works when/if I get a puncture. Anybody have any long-term experience with this stuff??
