7k miles and tires are Shot!

[Alan Smithee]

How is the ride and handling with the Toyos in 20"? I would like to get a set of M+S non-RFTs when the 20" Dunlops wear out (perhaps sooner than later after reading this thread), but I don't want to give up any of the handling, and I like the stiff ride (call me crazy). From what I have read, the Continentals are a compromise in this regard (not to mention, near impossible to find).

[soldmystang]

Originally Posted by Alan Smithee

How is the ride and handling with the Toyos in 20"? I would like to get a set of M+S non-RFTs when the 20" Dunlops wear out (perhaps sooner than later after reading this thread), but I don't want to give up any of the handling, and I like the stiff ride (call me crazy). From what I have read, the Continentals are a compromise in this regard (not to mention, near impossible to find).

are you driving on non-RFTs now Alan?

forgive me as i'm confused regarding your question. if your concern is that you will lose the handling from a RFT Dunlop by going to a Toyo then i say your worries are unfounded. any non-RFT is going to grip and ride better than a RFT tire IMO.

i can't speak for 20" Toyos. but i can tell you if you don't go with the XL (extra load) version you will have wasted your money.

i never get good mileage out of any tires i buy. that is before i put Toyo Proxes STIIs on my X5. maybe i got the fluke set Toyo puts out once every generation. damn good tires.

my wife's car uses Conti run flats summer version. got burned on a set of rears, 10K miles in seven months at close to $400. screw that, i went with non-RFTs from Conti with a 400 treadware. at half the price i might add. once the fronts wear out i will do AS tires there also.

the grip on these tires (Toyo proxes STIIs) impresses me. call me whatever JCL will, i think they are a damn fine tire for this platform.

[BGM]

Originally Posted by soldmystang

are you driving on non-RFTs now Alan?

forgive me as i'm confused regarding your question. if your concern is that you will lose the handling from a RFT Dunlop by going to a Toyo then i say your worries are unfounded. any non-RFT is going to grip and ride better than a RFT tire IMO.

Isn't grip based on how soft the compound is regardless if it's a RFT or not ? I thought this topic was covered in a previous thread awhile back--it's like beating a dead horse.

[JCL]

Originally Posted by BGM

Isn't grip based on how soft the compound is regardless if it's a RFT or not ? I thought this topic was covered in a previous thread awhile back--it's like beating a dead horse.

Yes, compound as well as tread pattern. Doesn't much matter if it is a run flat or not, as long as the tire remains in contact with the pavement. BMW claims that run flats will turn in better as well, for the same reason as people go to a low profile tire, less squirm.

[rh71]

Originally Posted by soldmystang

any non-RFT is going to grip and ride better than a RFT tire IMO.

... which is why I don't get all this argument for why summer tires are the only way to go on a "truck" like this. You can say BMW R&D spent all this time and effort to make the most optimally performing car, but then they gave it "inferior" RFTs for our convenience. Shouldn't they have gone summer non-RFT for the 20" wheel upgrade package if that was their intention?

[BGM]

Originally Posted by rh71

... which is why I don't get all this argument for why summer tires are the only way to go on a "truck" like this. You can say BMW R&D spent all this time and effort to make the most optimally performing car, but then they gave it "inferior" RFTs for our convenience. Shouldn't they have gone summer non-RFT for the 20" wheel upgrade package if that was their intention?

Because with the e70 along came the option of 3rd row seating (with no spare). Couple that with BMW going RFT on I believe almost all of their models with Sport Packages. As most know BMW has gone with RFTs as it believes safety is just as important as performance.

[JCL]

Originally Posted by rh71

... which is why I don't get all this argument for why summer tires are the only way to go on a "truck" like this. You can say BMW R&D spent all this time and effort to make the most optimally performing car, but then they gave it "inferior" RFTs for our convenience. Shouldn't they have gone summer non-RFT for the 20" wheel upgrade package if that was their intention?

You are lumping two very separate issues together. Yes, the RFT can ride more harshly. But it doesn't necessarily have lower grip, that is a function of things other than the run flat feature of the design. RFTs can just as easily have more grip. RFTs are claimed to have better turn-in (due to the stiffer side wall) which will improve performance in transients.

All design involves trade offs. Handling, noise, harshness, cost/mile, manufacturing cost, owner convenience, safety, etc. BMW engineers just found their own best balance across those items with RFTs, not necessarily the best in any one category.

Biggest reasons for run flats are packaging, convenience, and safety. Cost is actually higher, partly due to the need for a tire monitoring system. Packaging is obvious. Convenience: how many owners change their own flat tires any more? Now they don't have to. Safety relates to blow outs at speed. Not a common occurence these days IMO, but BMW can point out that the car will be more likely to stay in the lane. Most drivers of modern BMWs are not performance drivers, IMO. And as someone who does tend to critically evaluate my own tires, from the performance viewpoint, I didn't mind my run flats at all.

I predict that one day before too long, all tires will be run flats, just as it is very difficult to find non-radials these day. When radials first came out some didn't like them, as when they broke loose, they were less predictable, and less progressive. They gripped more, to a higher limit, and then let go more abruptly. We all got used to it. Look for the day when jacks and lug wrenches will be in the museum with the spark-advance cables and distributor caps.

[Alan Smithee]

Originally Posted by rh71

You can say BMW R&D spent all this time and effort to make the most optimally performing car, but then they gave it "inferior" RFTs for our convenience. Shouldn't they have gone summer non-RFT for the 20" wheel upgrade package if that was their intention?

To further JCL's point, the Corvette ZR1 has run-flats, and it is not at a loss for performance.

[soldmystang]

Originally Posted by Alan Smithee

To further JCL's point, the Corvette ZR1 has run-flats, and it is not at a loss for performance.

i'd be willing to bet that those folks that actually take their ZR1s to the track don't do it on RFTs.

RFTs on a ZR1 are perfect for the waxer crowd. which last time i checked is about 90%.