There are a lot of threads dedicated to dumping the RFTs in favor of "regular" tires. How bad are they really? Why would BMW make them OEM if they're that bad? I like the RFT concept. Does anyone have anything nice to say about the drivability of RFTs?

I will believe in run flat tires when BMW puts them on their M cars, and Porsche starts using them on 911's, Boxsters, and Caymans.

Only plus is that you can drive on them for a limited distance when they lose pressure, so that you're not left stranded in the middle of nowhere. You're not stranded till you get to the edge of nowhere and try to get one replaced.

i like them

for those days when i just can't figure out what i want to do with 200 dollars, and when i'm craving for that coveted horrendous tramlining, i go and order me a re050 rft.

ahhh, much better.

I disagree, treepusher.

Wait until you have your tire pressure drop to 0 psi like I did when I hit something in the road at 75 mph. My Z4 handled normally and I was able to handle the situation without any problems. I shudder to think what would have happened if the car had flipped or veered into the car on either side of me at that speed. I was about to replace the RFT with the non-flat kind, but no way now. The extra cost and the ride difference is nothing compared to greatly reducing the chances of wrecking the car and any injuries.

Each person has to make the choice as to what is truly important to them.

BMW uses RFT's for 2 reasons: 1. to save weight and 2. there's no room for a spare in the trunk (I've had Corvettes and Fiat Spiders with limited trunk space but they sat higher and the spares were mounted either under the trunk or in a deep well in the trunk).

I'm not a fan of runflats but I've never had a flat on my Z4. I feel sure they are safer in a flat tire situation. The Z4 handles great on good roads, but is not so great on rough and twisty mountain roads. I will take a close look at conventional tires when the time comes.

I hate the way they handle but they are good for one thing. I live in the DC metro area which is the land of giant potholes. I hit one the other night at about 40 mph, I was sure I was sure I bent a rim and destroyed the tire. Absolutely nothing bad happened, ya gotta love those sidewalls..

Wait until you have your tire pressure drop to 0 psi like I did when I hit something in the road at 75 mph. My Z4 handled normally and I was able to handle the situation without any problems.

Fair enough.. but, I've driven approximately 900k miles in my lifetime, and NEVER been stranded by a flat tire, much less had a catastrophic blowout. The odds just aren't that great that it's gonna happen. And a small car like the Z4 isn't likely to roll or go completely out of control, especially with a competent, alert driver. SUV's are another story, but we're not talking big hulks here.

What DOES happen is people get a punctured runflat, limp to some semi-nearby service station or tire shop, and way too often find places unwilling to patch the RFT's, don't have any (or at least the right matching one) in stock, and wham, you're essentially stranded, if not at the side of the road. A good friend of mine lost an entire weekend away from home wrestling with this very issue with his 650i, and soon after traded it in on an Audi and vowed never to own another BMW, he was so steamed at the whole incident and how unhelpful and unsympathetic BMW and the local stealerships were. With conventional tires, anyone with a cellphone and/or BMW Assist can call AAA or other roadside assistance and get flatbedded to that same nearby tire shop, and get that tire patched and be on their way.. or have much better odds of finding a replacement tire if that's necessary. Then factor in RFT's poor handling, tramlining, lousy durability/wear (due to the softened compounds in the RFT's to try to lessen the impact harshness), crummy ride quality, aforementioned impact harshness, and for me and many others, it's an easy decision to stick with "real" tires. Especially on a performance car. BMW M avoids these turds for good reason.

I like the firmness, however when I need to replace them, i'll go back to Conti Sport 2s.

Here's another very telling tidbit that more directly addresses the original question about drivability. The Bridgestone RE050A comes in a standard and runflat versions. The RFT was the OE tire on the '06 330i I owned before my M Coupe. Look at Tire Rack's survey ratings for both versions of this tire. In the ultra high performance category, there are 24 different tires ranked. The RE050A (non-RFT) ranks 8th out of 24, a pretty good showing. Same tire in RFT version ranks DEAD LAST, including a survey-low 3.8 rating in the "would you buy again?" category, and worst-in-class ratings in both ride comfort and noise comfort. Other categories have sucky scores as well. Huge huge difference, for what is otherwise the "same" tire. I got rid of the damn things at about 9k miles (in favor of PS2's) on that car and the transformation was incredible, it was like a completely different beast, with absolutely no negative tradeoffs other than the lack of a spare tire. To deal with that, I stuck a BMW mobility kit (electric pump & goo kit, same as comes with the M cars) in the trunk and was done with it. Best $1k I ever spent on any of my cars in memory.

Here's another very telling tidbit that more directly addresses the original question about drivability. The Bridgestone RE050A comes in a standard and runflat versions. The RFT was the OE tire on the '06 330i I owned before my M Coupe. Look at Tire Rack's survey ratings for both versions of this tire. In the ultra high performance category, there are 24 different tires ranked. The RE050A (non-RFT) ranks 8th out of 24, a pretty good showing. Same tire in RFT version ranks DEAD LAST, including a survey-low 3.8 rating in the "would you buy again?" category, and worst-in-class ratings in both ride comfort and noise comfort. Other categories have sucky scores as well. Huge huge difference, for what is otherwise the "same" tire. I got rid of the damn things at about 9k miles (in favor of PS2's) on that car and the transformation was incredible, it was like a completely different beast, with absolutely no negative tradeoffs other than the lack of a spare tire. To deal with that, I stuck a BMW mobility kit (electric pump & goo kit, same as comes with the M cars) in the trunk and was done with it. Best $1k I ever spent on any of my cars in memory.

So the Z4 Ms come with non-RFTs and a mobility kit in lieu of a spare? Is there any difference in the suspension on the Z4 M vs. a 3.0si sport package suspension, or is it essentially the same set-up? I guess what I'm asking is if I go with non-RFTs will the car be virtually identical in handling, during everyday driving, to an M (bigger engine notwithstanding)?

So the Z4 Ms come with non-RFTs and a mobility kit in lieu of a spare? Is there any difference in the suspension on the Z4 M vs. a 3.0si sport package suspension, or is it essentially the same set-up? I guess what I'm asking is if I go with non-RFTs will the car be virtually identical in handling, during everyday driving, to an M (bigger engine notwithstanding)?

Yes - there are NO M cars that come with runflats. No spare + mobility kit is the way they're sold. The suspension in the M Coupe & Roadster is different than the 3.0i sport, probably in lots of ways (shock valving, spring rates, fatter swaybars, harder bushings).

I might see where Fahrvergnugen is going. When BMW designed the suspension the sidewall stiffness was part of the design. No wonder they ride better with conventional tires. You have reduced the spring rate. Personaly I like having run flats better than I would like not having a spare. I have had a blowout at 80mph on the interstate. Changing the tire 5 feet from 80 mph traffic was not fun. GH

I like the concept, for all of the benefits stated above, but the tires simply aren't there yet for performance cars in terms of handling. I think they're a great idea for daily drivers, though even then I'd want better ride feel.

They aren't THAT bad. Honestly, they aren't horrible. They are a little rougher, they are heavy, and the lack of sidewall flex can give you issues when you are driving it hard. For most people, I think the runflat i just fine. I would have considered keeping them on my street wheels if they weren't so expensive.

no...not at all

I will believe in run flat tires when BMW puts them on their M cars, and Porsche starts using them on 911's, Boxsters, and Caymans.

Buggati Veyron has them, is that enough street cred???

DalTxZ4,

No, cars like that aren't driven very much. Viper, Corvette, Mini, and even Lexus SC among others come with them too, and those people have the same complaints if you go on their forums.

Its not about street credibility - I am sure run flats can handle high speeds - its about getting the best ride, performance, and value combination. I have been lucky. I have had about three flat tires in about 35 years of driving - the last one being only last year on my wife's Honda Pilot - and they were all slow leakers due to screws or nails.

If you like run flat tires, good for you! They are safe.

So why don't M cars and Porsches use them? I can only conclude that they are not the best tire for the car with respect to ride and performance.

I have never driven on RFTs but I can tell you this. I've been riding motorcycles for 40 years; everything but crotch rockets. My Z4 M doesn't use RFTs an I am constantly amazed at corners I can take faster and more comfortably than I can on a bike.

I have never driven on RFTs but I can tell you this. I've been riding motorcycles for 40 years; everything but crotch rockets. My Z4 M doesn't use RFTs an I am constantly amazed at corners I can take faster and more comfortably than I can on a bike.

cornering is the one thing that cars are supposed to be able to do ebtter than a bike.

it's a 2 wheels vs 4 wheels thing. nothing against a bike, but outright grip in a turn and just the physics of how bikes go around corners, allows cars to carry more speed through turns.

but obviously the bike makes up that time easily with it's acceleration.

Fair enough.. but, I've driven approximately 900k miles in my lifetime, and NEVER been stranded by a flat tire, much less had a catastrophic blowout. The odds just aren't that great that it's gonna happen.

That's good for you, that you are so lucky. If you want to base your safety on luck, that's your decision, I won't try to tell you otherwise.

I agree 100% that there are the exact issues you mentioned in your post that are not in favor of RFTs.

That's good for you, that you are so lucky. If you want to base your safety on luck, that's your decision, I won't try to tell you otherwise.

Tires are a LOT better than they used to be.

Car companies were moving away from giving people spare tires before run-flats made the scene. Apparently only about 5% of the population has ever had a flat tire; of that 5%, most people get slow leaks from picking up screws and nails that they can have the tire repaired before it strands them, or use fix-a-flat to keep going.

I looked into this when I took the RFTs off my 2.5i and put on Goodyears. I was encouraged by the fact that in 30 years of driving, I've never had a flat.

Tires are a LOT better than they used to be.

Car companies were moving away from giving people spare tires before run-flats made the scene. Apparently only about 5% of the population has ever had a flat tire; of that 5%, most people get slow leaks from picking up screws and nails that they can have the tire repaired before it strands them, or use fix-a-flat to keep going.

I looked into this when I took the RFTs off my 2.5i and put on Goodyears. I was encouraged by the fact that in 30 years of driving, I've never had a flat.

I'd agree with you, but make this note. Been driving since my sixteenth birthday--that's forty years ago, and yes, I've made occasional stops to eat and sleep--and can count my flat tires on one hand. Two of them on a 2005 330i, and one on my wife's X3, all within the last two years. All picked up metal of some sort--a screw, a nail, and a hunk of something--and all were deemed 'unrepairable' by my local dealer. $$$

Fortunately, none of the failures were catastrophic, just aggravating. Still, that's three within the last two years, and I don't spend a lot of time on the road these days.

That said, the RFTs stink. They're the poorest-riding tires I've ever used. The unpredictable tramlining as the car jerks left or right scares hell out of me, and I removed them from the Z within the first month, with no intention of ever using them again.

I'd rather take my chances with a decent ride on good non-RFTs, and if that means I might get stuck now and then, so be it. BMW may see RFTs as a convenience or safety issue. To me, the poor ride and miserable handling outweigh any such considerations.

I can't justify the expense of replacing my RFT's right now. When the time comes, I will replace them with non-RFT's, and I'll go the extra mile and have an extra rim with spare in the trunk area, secured in some way. If I didn't use my z4 in autocross, I'd probably stick with RFT's though just out of convenience.

RFT's seem like a good idea, but honestly I can't remember the last time I had a flat tire that left me stranded somewhere.

Is there a 'Space Saver' tyre available for the Z4? Lots of manufacturers use these in lieu of a full size spare. Problem solved!

LeatherZ sells a jack kit and space saver, but they take up a lot of trunk space.

RFT's seem like a good idea, but honestly I can't remember the last time I had a flat tire that left me stranded somewhere.

You know, that's actually a good point. That's why some manufacturers are have gone to space savers or no spare at all (with a mobility kit). It's an infrequent problem. I have AAA and they are my backup.

I have been seriously considering the LeatherZ space saver, but it's an expensive and inconvenient fix. I think the tire and jack kit are about $345. And you lose about 40% of your trunk. It's really up to every individual and what you feel comfortable with. I live in a pretty rural area, so a flat at night waiting for AAA is no big deal. However, if my regular route included the inner city, I might feel differently. Just another point, my wife would NEVER change a tire, she would just call AAA.

What tire pressure are you running in your rft"s? When I bought my car tires were about 80% gone. Ride was terrible and handling was worse. Checked inflation and found them to have psi of approx. 25 psi. I increased inflation to 32 psi with improved handling. After reading about improved handling of non rft tires I was leaning toward non rft replacements. However, due to fact that I use car for long distance trips I went back to rfts. Tire shop stated tires should be inflated to 45 psi. I thought this was nuts, but the car now rides and handles like a completely different car. I would love some feedback from anyone if they have seen similar results. Is this inflation press. of 45 psi nuts. I feel I may have lost some lateral grip at this pressure.

What tire pressure are you running in your rft"s? When I bought my car tires were about 80% gone. Ride was terrible and handling was worse. Checked inflation and found them to have psi of approx. 25 psi. I increased inflation to 32 psi with improved handling. After reading about improved handling of non rft tires I was leaning toward non rft replacements. However, due to fact that I use car for long distance trips I went back to rfts. Tire shop stated tires should be inflated to 45 psi. I thought this was nuts, but the car now rides and handles like a completely different car. I would love some feedback from anyone if they have seen similar results. Is this inflation press. of 45 psi nuts. I feel I may have lost some lateral grip at this pressure.
At 45PSI, you will probably wear out the centre of the tyres while only having half worn the outside edges of the tread. Your lateral grip may be less due to a smaller contact patch with the road.

I actually kinda like the sidewall stiffness on superspooth road or track and going semi quickly and don't mind the traction... But would way rather not have them.

Didn't hate em so much I would trash em until they're used up.

Robust discussion we have here! Good points. RFTS in my past. Can of goo & air compressor + cell phone best I can do for now.

RFT's? Great idea... poor execution. Nice to not be stranded if and when you get a flat. For straight driving on smooth roads and highways, they are fine. Where they fail is on rough roads and performance driving where braking and turning is involved. I switched back to my RFT set for a long road trip to New Hampshire Memorial Day weekend. My back still hurts. AutoXing, I use Eagle F1's... they easily beat out the RFT's in every way. RFT's are too stiff in the sidewall... no flex, they just let loose with little warning.

Also, the big problem I ran into was that no one stocked Bridgestone RFT's. The dealer wanted me to show up in person, make a deposit and then they would order them for me... 5-7 day wait. WTF? Tirerack had them to me in 2 days at almost half the price. Still, if you got a flat and it wasn't fixable... where would that leave? In limbo until someone could get a replacement to you. Ummm.. that would suck worse... JMTC

In car like the Z4 with limited trunk space, I will be keeping the RFT's. They do have a stiffer ride, but I am not about to give up what little trunk space there is, even if it is more than some of the other roadsters out there. Also, it is a nice safety feature from my perspective. I have already had one occasion with a nail. I did not have to attend to it until the next day when I took it into a tire shop for repair. And, yes, they can repaire RFT's, just like regular tires, as long as the puncture is in the tread and not the sidewall.

I endured 3 years of RFT's in my 04 Z4, then I figured out I could replace them with non-RFT's. What an improvement!!! The ride and handling were dramatically changed for the better.

So I agree that a can of fix a flat and a compressor are the way to go.

Plus it was costing about $400 to replace the tires. Thank God that I went with the tire & wheel warranty!!! I went through 7 replaced tires. Then in around 2007 they had an epiphany. Hey!! We can actually repair these things!! Gee thanks.....