New shoes rock!

[erichui]

guys, I got a question, will the wider tires you guys getting (275 compare to stock 255), would it throw off the speedo by much? since the speed cameras over here are pretty strict..... thanks

[maxzander]

Originally Posted by marcw

Finally ditched the runflats today. Even on the short drive home from the tire shop the difference was like night and day. I went with the ever so popular Conti ExtremeContact DWS all seasons in 225/35/19 and 275/30/19. Ride quality has much improved. Going over manhole covers no longer feels like the car is in an earthquake. The tires are very quiet compared to OEM. Steering feels lighter. I'm going on a 300 mile drive on Saturday which gives me plenty of time to break them in.

I can wholeheartedly agree with everybody on the board to ditch the runflats! I should have done this 3900 miles ago. Feels like a completely different car.

-Marc

PS: If anyone is interested in buying my barely used Bridgestones for track tires PM me. I bought a tread depth gauge today so I can measure remaining tread on them.

congrates!!!! i ditched my RFT the 2nd day i got my ride... the comfort effect is instantaneous!!!

[alan64]

interesting article.... http://editorial.autos.msn.com/artic...mentid=1160468

[marcw]

275 will be 1.875% too slow compared to stock size. Plus BMW is always way conservative with their speedo.

Originally Posted by erichui

guys, I got a question, will the wider tires you guys getting (275 compare to stock 255), would it throw off the speedo by much? since the speed cameras over here are pretty strict..... thanks

[Memphis1]

Originally Posted by marcw

275 will be 1.875% too slow compared to stock size. Plus BMW is always way conservative with their speedo.

Erichui,

That's if you keep the same aspect ratio, so it's not the width of the tire is the fact that you're keeping the aspect ratio the same. In theory you should be able to keep the same radius size by playing with different combination of width and aspect ratio so that you remain at OEM radius

[mcbeee]

Originally Posted by marcw

Finally ditched the runflats today. Even on the short drive home from the tire shop the difference was like night and day. I went with the ever so popular Conti ExtremeContact DWS all seasons in 225/35/19 and 275/30/19. Ride quality has much improved. Going over manhole covers no longer feels like the car is in an earthquake. The tires are very quiet compared to OEM. Steering feels lighter. I'm going on a 300 mile drive on Saturday which gives me plenty of time to break them in.

Can't wait, I've almost burned off the rears ....have 26000kms so far of a very rough ride..

[marcw]

True. However, I wanted to keep the same profile so I have a higher sidewall. With my 19" rims I need all the protection I can get. I'm willing to give up on the low low profile look if it saves me from having to buy yet another rim.

Originally Posted by Memphis1

Erichui,

That's if you keep the same aspect ratio, so it's not the width of the tire is the fact that you're keeping the aspect ratio the same. In theory you should be able to keep the same radius size by playing with different combination of width and aspect ratio so that you remain at OEM radius

[Silver-Bolt]

Also the wheel width will affect the rolling diameter as well. Typically most factory speedo's indicate faster than actual speed. The slightly taller tire will likely correct that. Miles won't rack up quite as fast either.

[erichui]

thanks for the answers guys! Everything is much clearer now.

That table with all the specification was very helpful too.

[UncleScottie]

Originally Posted by alan64

interesting article.... http://editorial.autos.msn.com/artic...mentid=1160468

"From a pure conservation point of view, run-flats are a green choice."

Hmmm! Get a flat with a run flat and few BMW dealers or authorized Bridgestone dealers, if any, will repair it. Must be replaced with a new tire regardless of how few miles you might have on it. Get a flat with a conventional tire and it can be repaired and finish out a full life.

Yep, sounds greener to me.

Besides, going with just 4 conventional tires and no spare, as BMW does on M cars, would be even greener. They use less rubber than run-flats and have lower rolling resistance for better fuel economy. Calling run-flats green is pure hype.

[Memphis1]

^^ theres a huge difference between creating and adding a fifth tire and wheel on every single car than to fix a few tires or even replace them.

[UncleScottie]

Originally Posted by Memphis1

^^ theres a huge difference between creating and adding a fifth tire and wheel on every single car than to fix a few tires or even replace them.

Exactly, that's why going with just 4 conventional tires and no spare, like on the BMW Z4 M Coupe, Porsches, Acura NSX, etc., is the true green choice.

[Memphis1]

Maybe I misunderstood you.

all BMW's have run flats except for the M cars, hence runflats are a green choice because they make a fifth wheel obsolete.

[cdeslandes]

Originally Posted by UncleScottie

"From a pure conservation point of view, run-flats are a green choice."

Hmmm! Get a flat with a run flat and few BMW dealers or authorized Bridgestone dealers, if any, will repair it. Must be replaced with a new tire regardless of how few miles you might have on it. Get a flat with a conventional tire and it can be repaired and finish out a full life.
...

Modern high-performance tires aren't often fixable after a flat, be they run-flat or not. Especially if the puncture is in the sidewall - a common result of low-profile tire/pothole interaction.

My wife and I have had 3 flats in as many years, every time the tire had to be replaced and these were not run-flats.

[gblansten]

Originally Posted by cdeslandes

Modern high-performance tires aren't often fixable after a flat, be they run-flat or not. Especially if the puncture is in the sidewall - a common result of low-profile tire/pothole interaction.

My wife and I have had 3 flats in as many years, every time the tire had to be replaced and these were not run-flats.

Amen. I wouldn't trust a high performance tire after a puncture. I've had two flat in the last few years. I also replace the opposite side tire at the same time.

[Mr. ///M3 RD]

Originally Posted by alan64

interesting article.... http://editorial.autos.msn.com/artic...mentid=1160468

Alan,

Thanks for posting this link! It is so interesting I am posting a new thread above, so everyone can comment.

It is in fact so interesting I will also start a thread in the Tire Rack Forum

Look for .... The RFT Saga Continues …

Thanks again

[Rafale]

The rhetoric although not completely absurd is very challenge-able. Ok, So the tires are called greener because they allow manufacturers to not put a spare tire on the car. The problem is the weight you gained from not putting a spare tire is completely lost in the unsprung weight added to the tires. In terms of rolling resistance and unsprung weight, the car even could consume more gas. Why not learn from VAG who put a flat inflatable spare which is lightweight and saves space? The rubber saved from the spare tire is actually evenly distributed into the four tires in the car arguably more rubber is being used. In my particular case I have saved 5lbs front 6lbs rear by going to regular tires. That's 22lbs of unsprung weight; 22lbs of mostly rubber. It is the same weight as a full size tire! The small spare on an Audi weights about this much with the wheel and if we believe the 4x formula I reduced my car the equivalent of 88lb by switching my tires!
The added safety argument is really marginal at best and in my view. It is more of a marketing line item than anything else.
I believe there are cases where the RFTs workout really well but not on sport cars with low profile tires...

[Memphis1]

havent you guys learned anything?? is all about marketing, just like GM lied about its hybrid car.

[Mr. ///M3 RD]

Originally Posted by Rafale

The rhetoric although not completely absurd is very challenge-able. Ok, So the tires are called greener because they allow manufacturers to not put a spare tire on the car. The problem is the weight you gained from not putting a spare tire is completely lost in the unsprung weight added to the tires. In terms of rolling resistance and unsprung weight, the car even could consume more gas. Why not learn from VAG who put a flat inflatable spare which is lightweight and saves space? The rubber saved from the spare tire is actually evenly distributed into the four tires in the car arguably more rubber is being used. In my particular case I have saved 5lbs front 6lbs rear by going to regular tires. That's 22lbs of unsprung weight; 22lbs of mostly rubber. It is the same weight as a full size tire! The small spare on an Audi weights about this much with the wheel and if we believe the 4x formula I reduced my car the equivalent of 88lb by switching my tires!
The added safety argument is really marginal at best and in my view. It is more of a marketing line item than anything else.
I believe there are cases where the RFTs workout really well but not on sport cars with low profile tires...

I think the BMW team that made the decision to embrace RFT for every BMW car except for the M should assemble in Donald Trump's Board room and one or two will be fired .... I love to see it, let me rephrase that I'll pay to see that.

[Mr. ///M3 RD]

Originally Posted by Memphis1

havent you guys learned anything?? is all about marketing, just like GM lied about its hybrid car.

Yes it is and they will pay for it dearly ... consumers are getting smarter.

[nicolak]

I have read many post stating the change between the run flat tires to conventional tires is remarkable. I suppose I am a bit skeptical and doing it may be the only recourse.

I purchased my vehicle mostly for recreational traveling, it is a weekend car only. The numb center steering, the constant need for correction, the harsh ride, and the terrible pulling/drifting on B roads has become unbearable. To confirm, will switching the tires make all that much of a difference? So much so I can drive my car again without cursing. I contribute most of the above problems just to the sporty nature of the chassis, I hope to be wrong.

Plan 'c' is to change vehicle entirely. Received a non offensive trade in offer, going to test drive the model posted this weekend. Any additional input about the tire change would be great, mostly interested in motorway improvement, does the car track straight with less wandering and need for corrections. Thank you.

[DrewKo]

I personally believe the best modification you can make to a recent year BMW is removing the RF tires and replacing them with non RF tires. The difference is significant.