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[daves335i]

Being new to runflats, and then having to take them off and put on non-runflat winter tires (REVO1), I've heard everyone talk about how crappy they are.

Why? what makes runflat "performance" tires soo bad?

[BMW F22]

As far as traction I havent noticed anythin "bad" about it. As far as the ride I guess they are stiffer/more harsh than non-RFTs. Since they are "perfomance" tires they're not meant t be driven in the snow. But on dry roads they seem to perform fine for me (again the ride is a lil harsh).

[rjm]

I sure have been happy with mine. They are Bridgestone Potenzas and the ride and handling has been great. I adjust the pressures to the recommended optimum pressures every few weeks and I have been very pleased with them. I don't know what all the complaining is about.:rocks:

[Russellnyc]

+1

I like the ride comfort a lot, and I'm comparing them to lots of tires I've used: a couple different types of Bridgestone Potenzas, Falkens, Yokohama AVS, and Michelin PS2s.

[RiXst3r]

They did some magic in the coupes suspension to "design" it for runflats according to BMW... not sure if this is BS, but the only thing i notice about my runflats is some extra road noise, mostly when its really cold out....

[StewtheBassman]

It seems the only really BAD RFTs are the 16" Turanza EL42s. Don't worry if you have anything else and/or are a weight freak.

[NFS13]

I think what it really comes down to is the way you drive your vehicle and what you expect from the ride. I swapped the RFT's because I felt they were way too bouncy over bumps at higher speeds. When hooked up in a turn, if I hit even a small bump, the tires would bounce causing the car to kick out, not a confidence builder. I also felt that they lost a lot of grip below 40 degrees, and if it was raining at those temps, holy crap the car felt loose!
Since I changed to non-RFT's I have eliminated all the issues above and lessened the road noise, which was not a deal breaker for having them.

[Jaws]

Originally Posted by BMWE90

As far as traction I havent noticed anythin "bad" about it. As far as the ride I guess they are stiffer/more harsh than non-RFTs. Since they are "perfomance" tires they're not meant t be driven in the snow. But on dry roads they seem to perform fine for me (again the ride is a lil harsh).

RFTs are just like regular tires. They make winters, all-seasons, etc. Any type of summer tire shouldn't be driven in snow, be it RFT or not.

[wheeler]

I hated them. The car felt 'twitchy,' not quite tramlining, but not quite running straight either. Took two hands on the wheel to keep it in a straight line. They're also heavy.

I replaced wheels and tires at the same time, went from 17" RFTs to 19" Toyos, +2 width, Volk wheels. Cut a total of 50 lb of unsprung weight. What a difference. I don't have any way to measure the gains, but I know the car's skidpad and 0-60 numbers are way better than before.

RFTs are good for only one reason - safety. In all other aspects I think they are inferior.

[BK]

I think the biggest deal is that they're heavy. They're also expensive and almost impossible to repair, if you believe the dealers. They don't seem to wear very well for most people -- people are seeing "feathering" and getting a lot of noise after relatively few miles on the tires. Finally, the 255mm rear RFT summer tires are out of stock most places.

As for the ride, I think the summer RFTs ride great. I like them, but am not looking forward to the bill for replacing them all after 15K miles or so.

[dazzab]

The stiff sidewall of the RFT's that is needed to prevent sudden deflation if the tyre is punctured is the cause of why many drivers recject them.

This makes the car skittish (depending on the road surface) over bumps, repaired road sections, in fact anything when the road is other than smooth.

I replaced mine after just 3,000km and the improvement in ride is dramatic (and this was before I had joined this BMW forum so I can honestly say I wasn't influenced by the bad press they receive here).

Grip from the OE Bridgestone RFT's RE050's was never the problem just a serious lack of ride quality.

[sdiver68]

Originally Posted by dazzab

The stiff sidewall of the RFT's that is needed to prevent sudden deflation if the tyre is punctured is the cause of why many drivers recject them.

Grip from the OE Bridgestone RFT's RE050's was never the problem just a serious lack of ride quality.

Just remember "skittish" to 1 person is "responsive" to the next. Track people and racers appreciate a stiff sidewall.

[NFS13]

Originally Posted by sdiver68

Just remember "skittish" to 1 person is "responsive" to the next. Track people and racers appreciate a stiff sidewall.

Yeah but you will never find THAT stiff of a sidewall on a race tire. I am sure you wish you could, but the performance would be horrible due to compound differences between the sidewall and the tread.

[UncleWede]

Just thinking of two on-off ramps I normally drive. On-ramp, just as I go to merge into traffic, there is a slight difference in the pavement. The "effort" to get over that little hump scares my wife, I hold on with both hands now. Off-ramp has about 20 degree bank, and in the middle of the curve it switches from asphalt to concrete. It feels like the car literally jumps there and follows the tangential course, which is unfortunately into the parallel lane of traffic. A definate 2-hander!
Oh, and I need to change my tires BEFORE my oil, even though I replaced one that had a nail more than 3 inches off centerline and couldn't be repaired. That 1 tire cost me $260, and we couldn't really drive for 4 days while waiting for the replacement.
Yep, those wonderful 16" Brisdgestones.

[dawgdog]

I switched the runflats out on my 550 for 19" Michelin PS2s and the change was dramataic. I recently switched out the runflats on my 335 for 19" wheels with PS2s and the change was not nearly as dramatic. I'm not sure it is much smoother, and the steering feel is not dramatically improved like it was in the 5. Tramlining really is not an issue on either set of tires in the 3, whereas with the 5 it tramlined like crazy on the 18" runflats. Now, with the 550 I was going from 245/18 275/18 to 245/19 275/19, whereas on the 335 I am going from 225/18 255/18 to 245/19 and 275/19. My impression is that the runflat tires are much better tuned to the 3 series than the 5, and that probably these tires are better runflats. Conclusion: though there are some possible improvements with the switch to nonrunflats, the switch is not the no-brainer it is in the 5 series.

[dazzab]

Quote:
Originally Posted by sdiver68
Just remember "skittish" to 1 person is "responsive" to the next.

Yeah if they don't understand English!

Quote:
Originally Posted by sdiver68
Track people and racers appreciate a stiff sidewall.

Agreed, but there are still better tyres available than the RFT's we are talking about if you want to play boy racers.

[850CSi]

My 16" Turanzas suck.

[sdiver68]

Originally Posted by NFS13

Yeah but you will never find THAT stiff of a sidewall on a race tire. I am sure you wish you could, but the performance would be horrible due to compound differences between the sidewall and the tread.

http://www.kumhousa.com/Products/Ptn...tion=PtnDetail

High ply turn-up and additional nylon reinforcement provides stiff sidewall construction.

[sdiver68]

Originally Posted by dawgdog

I switched the runflats out on my 550 for 19" Michelin PS2s and the change was dramataic. I recently switched out the runflats on my 335 for 19" wheels with PS2s and the change was not nearly as dramatic. I'm not sure it is much smoother, and the steering feel is not dramatically improved like it was in the 5. Tramlining really is not an issue on either set of tires in the 3, whereas with the 5 it tramlined like crazy on the 18" runflats. Now, with the 550 I was going from 245/18 275/18 to 245/19 275/19, whereas on the 335 I am going from 225/18 255/18 to 245/19 and 275/19. My impression is that the runflat tires are much better tuned to the 3 series than the 5, and that probably these tires are better runflats. Conclusion: though there are some possible improvements with the switch to nonrunflats, the switch is not the no-brainer it is in the 5 series.

Shhh! Don't let experience ruin the anti-RFT crowd!

[NFS13]

Originally Posted by sdiver68

http://www.kumhousa.com/Products/Ptn...tion=PtnDetail

High ply turn-up and additional nylon reinforcement provides stiff sidewall construction.

Wow, I need to read up on that design, thanks!

[s4iscool]

you only want a stiff sidewall to a certain degree. Race tires for F1 and motogp are designed to provide a certain level of flex in order to increase road sensitivity to the driver/rider. So to say that racers want the stiffest sidewall is wrong. The RFTs are too stiff imo, and I look forward to ditching them. Many others I know have replaced theirs within 500 miles of owning the car.

[boyce'06 330i]

Originally Posted by s4iscool

you only want a stiff sidewall to a certain degree. Race tires for F1 and motogp are designed to provide a certain level of flex in order to increase road sensitivity to the driver/rider. So to say that racers want the stiffest sidewall is wrong. The RFTs are too stiff imo, and I look forward to ditching them. Many others I know have replaced theirs within 500 miles of owning the car.

Correct. In a race tire you want compliance, grip, steering response and predictability at the edge of traction. These are not qualities of a stiff sidewall.

The suspensions in race cars (F1) are so stiff to reduce body roll, squat and diving, that a stiff sidewalled tire would make the car unpredictable over the slightest of bumps. A scary thought at 190 mph!