Bridgestone Potenza Runflat .... safety hazard

[haraldo]

I never before used runflat tyres before

But got a shock when I changed from winter tyres to summer tyres on our BMW 3 series 2007 coupe, the winter tyres are Dunlop (something) 225/45 17, medium hard tyres and the car behave extremely well with these....

we bought the car secondhand last fall and never used the summer tyres, but now when changing to these Bridgestone Potenza Runflat 225/45 17 the car behaves like it's being controlled by forces from outer space, 1000% sure that there's nothing wrong with car and rims.

The tyres are so hard it fells like they're made of solid stone..... and they're so hard that anything that remotely looks like uneven surfaces are being pushed right back to the steering wheel, and here in Norway the roads are far from being perfect. It's very common, especially in tunnels, that there are significant tracks in the asphalt due to the simple wear from spiked winter tyres. The car is now extremely susceptible to these tracks and it's even to the point of being dangerous to drive. If noit holding very well on the steering wheel it may even be dragged right out of your hand due to significant forces coming from the wheels

Talked to several tyreshops and the only thing they can say is that the Bridgestone runflat tyres behave like this and this is normal... suggest changing to Michelin tyres, well nice suggestions

Standard pressure is 2.1 psi, I have tried with lower and higher pressure from 1.9 to 2.7 psi... and... somehow imagine this to be slightly improved by lowering airpressure to 1.9 psi, but I'm not really sure...

Are there any suggestions? before I go to the point of changing tyres (to NON RUNFLAT technology) Is the Runflat technology really so troubled, and if so why the he%¤#% are cars equipped with runflat technology in the first place, they're supposed to make cars safer, not less safe.....

 

[chris357]

yeah they are hard because they have reinforced sidewalls.. which removes any flex that the tire has at all, and they are super expensive. dont forget you dont have a spare tire especially in the winter since your winter tires are not run flat.

 

[haraldo]

Of course I know they are hard, but that they ruin the driving capabilities of the car is news to me .....

 

[chris357]

Honestly I've driven alot of BMW's (I used to sell them) and I never really noticed a huge difference in the drive.. but winter tires are really soft so maybe the contrast between the two makes it more pronounced.. go to a dealer and drive a new one and see if it feels the same

 

[haraldo]

Honestly I've driven alot of BMW's (I used to sell them) and I never really noticed a huge difference in the drive.. but winter tires are really soft so maybe the contrast between the two makes it more pronounced.. go to a dealer and drive a new one and see if it feels the same

Of course, difference in road conditions make lots of difference, if your roads are 100% flat and even you will never feel this difference.....

But yes, it's a good idea, thx

 

[chris357]

i'm in chicago suburbs, we have 2 seasons winter and road construction and you are welcome,

another idea might just be to take it to service most bmw dealers give free loaners this way you dont have to deal with a salesman.

 

[haraldo]

i'm in chicago suburbs, we have 2 seasons winter and road construction and you are welcome,

another idea might just be to take it to service most bmw dealers give free loaners this way you dont have to deal with a salesman.

ha ha, my pleasure.......

Well yes, I'm gonna go to local BMW dealer, they're sometimes even helpful, perhaps they can come up with something
THX for your ideas Chris !

 

[chris357]

anytime, i am suprized BMW decided to go that way since they are so crazy about drive quality and handling. I guess the wieght of the spare is a bigger deal to them?

 

[Wannabubble]

I used to work for Bridgestone/Firestone and I would steer clear from the RFTs unless you are on good roads and loaded with money. But I would stick with Bridgestone.

If ya want performance tires I would go for something like these:

http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE960AS+Pole+Position&partnum=245WR7RE960PPXL&vehicleSearch=false&fromCompare1=yes

http://www.tirerack.com/tires/tires.jsp?tireMake=Firestone&tireModel=Firehawk+Wide+Oval+Indy+500&partnum=245WR7FHWI5XL&vehicleSearch=false&fromCompare1=yes

If ya want cruising tires, try these:

http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Turanza+Serenity&partnum=245WR7TS&vehicleSearch=false&fromCompare1=yes

 

[jostenmeat]

anytime, i am suprized BMW decided to go that way since they are so crazy about drive quality and handling. I guess the wieght of the spare is a bigger deal to them?

I think it was about safety, and their (perhaps inaccurate, who knows) guess at what consumers wanted. I think I have learned that the weight saving (if any) is not the issue/point, but the increased "unsprung weight" of the heavier RFT is the biggest factor in performance compromise, AFAIK.

That said, I came across this article, and people who use RFT are hoping that the 3rd generation will finally get rid of the harsher ride.

http://www.autoblog.com/2009/07/06/reviewed-bridgestone-3g-rft-tires-taking-the-shock-out-of-run/

 

[j_garcia]

I actually got a flat on the freeway at 80mph in the fast lane on my RE760s and I was still able to control the car to the point where I was able to drive over to the right and exit the freeway. No damage to the rim (and my rims aren't cheap...) but the tire was toast as expected. Bridgestones are my preferred tires over anything else. I would also recommend staying away from RFTs.

 

[chris357]

I think it was about safety, and their (perhaps inaccurate, who knows) guess at what consumers wanted. I think I have learned that the weight saving (if any) is not the issue/point, but the increased "unsprung weight" of the heavier RFT is the biggest factor in performance compromise, AFAIK.

That said, I came across this article, and people who use RFT are hoping that the 3rd generation will finally get rid of the harsher ride.

http://www.autoblog.com/2009/07/06/reviewed-bridgestone-3g-rft-tires-taking-the-shock-out-of-run/

i woudl have to imagine once that happens alot of other companies will start using them

 

[haraldo]

I actually got a flat on the freeway at 80mph in the fast lane on my RE760s and I was still able to control the car to the point where I was able to drive over to the right and exit the freeway. No damage to the rim (and my rims aren't cheap...) but the tire was toast as expected. Bridgestones are my preferred tires over anything else. I would also recommend staying away from RFTs.

Well I had an explosion on Michelin Maxi-Ice ordinary (Not run flat) winter tyres in a fully loaded car in 70mph..... no problems, no issues to control car, no damages to rims.....

For me the runflat tyres is just a marketing jumbo mumbo......

 

[Wannabubble]

Well I had an explosion on Michelin Maxi-Ice ordinary (Not run flat) winter tyres in a fully loaded car in 70mph..... no problems, no issues to control car, no damages to rims.....

For me the runflat tyres is just a marketing jumbo mumbo......

Not complete jumbo. They are certified to go 50 miles at 50mph when they get a flat.

 

[highfigh]

i'm in chicago suburbs, we have 2 seasons winter and road construction and you are welcome,

another idea might just be to take it to service most bmw dealers give free loaners this way you dont have to deal with a salesman.

I have driven through/in Chicago in Winter- you have one season and it's called Road Construction.

Did you sell at Knauz?

 

[Shock]

I think your browser spell check is set to "Ye Old English"

 

[haraldo]

Not complete jumbo. They are certified to go 50 miles at 50mph when they get a flat.

Not so much Jumbo perhaps, but definitely Mumbo.....

 

[chris357]

I have driven through/in Chicago in Winter- you have one season and it's called Road Construction.

Did you sell at Knauz?

Motor Werks, in barrington its a prtty nice place too. Knauz is really nice from what I hear.