Another Potenza Runflat question

epiphone3 · 03-16-2007, 12:11 PM

Quote:

Originally Posted by bnj

That's the thing, you were already grinning by the time exiting the parking lot of the tire store.

You had an opinion already before driving. Of course, because you had made a choice already. You experience what you expect to experience. Moreover, new tires are better than old, and of course in a perfect balance.

I have been driving and tracking many Beemers with RFTs and non-RFTs. Same size RFTs are less comfortable, but appr. a second per kilometer quicker.

I am open to all choices when the time comes for the next set for my personal daily driver e92 335i. However, saying that Potenza RE050A RFTs suck is ignorance. Especially mated with e92 335i OE suspension they are fabulous performance wise. The thread is about Potenzas, not about Runflats in general.

Traditionally, European taste is towards performance & handling rather than comfort. It's understandable that I like my suspension (springs+shocks+tires) to be stiffer than you. I couldn't think of having my 335 without sport suspension or minimal flex in tirewalls. The turn-in must be sharp and I don't want my tires to wrap from the wheels in a fast curve, but be in a parallel with the ground offering the most grip. I have a tarmac rally suspension in my Integrale, and that has all the suspension elements a lot stiffer than my Bmw. Whatever funny theories people have here, the truth is that a fast tarmac suspension is very very stiff compared to any ordinary car suspension.

However, for your taste you can make a good choice having non-RFTs when its time to replace your old tires. But if you say my current tires are not good for me, I expect you even try to give me some facts. Because its quite bold of a statement. Especially, since I have been driving quite a lot of e92 335i at non-RFT's.

I am running the Potenza RFTs on my E90 323i Sport and all I can say is put 15000 kms plus on the Potenza RFTs and maybe you will agree with me that they suck. They get noisier, make a humming noise between 60 kph and 80 kph, and perform poorly on uneven pavement.

I don't like how the RFTs degrade... rather than just lossing rubber, they deform and cup for no reason. This is what pisses me off especially when you pay an arm and a leg for RFT Potenza tires.

I'd rather go non-RFT and have a set of tires that peforms effectively over the life of the tires rather than get RFTs that perform better when new and then degrade savagely over the life of the tire.

I couldn't care less about being faster around a race track. Try putting 15,000 km on a RFT potenza and 15,000 km on a standard Potenza and see who is faster more consistently on the track... I'd be curious to find out.

Richwm · 03-19-2007, 03:28 PM

Quote:

Originally Posted by KevinC

ANYONE trying runflats and "real" tires back-to-back on an E90/92 would have the same impression. Hell, I was already grinning by the time I exited the parking lot of the tire store. I've yet to see anyone who's made the switch do anything but rave about the upgrade. OTOH there are plenty of people who never have experienced both who are steadfastly defending runflats. Ignorance is bliss I suppose. Too bad, they're missing out on turning their great car into a really great car.

I couldnt have said it better.

You guys that think the stock tires have better grip read this from Car and Driver http://www.tirerack.com/images/tires...y_f1_gs_ds.pdf

N1 · 03-23-2007, 03:29 PM

BMW Run-Flat Tires Video http://www.metacafe.com/watch/333266...un_flat_tires/
only for drivers with hands.

agh! · 03-26-2007, 07:18 AM

In this RFT's are OK / not OK debate, lets throw into the ring the fact that September 2006 build dates onwards have a different part number for struts than pre-Sept 2006 cars. This could mean that is is not an E92 vs. E90/E91 issues at all, it could be down to new improved suspension set up.
An E91 owner I know who historically hates RFt's on 1 and 5 series finds them absolutely fine so far on his October/November 2006 built E91 335i.

bnj, when was your car built?

bnj · 03-26-2007, 08:09 AM

Quote:

Originally Posted by agh!

In this RFT's are OK / not OK debate, lets throw into the ring the fact that September 2006 build dates onwards have a different part number for struts than pre-Sept 2006 cars. This could mean that is is not an E92 vs. E90/E91 issues at all, it could be down to new improved suspension set up.
An E91 owner I know who historically hates RFt's on 1 and 5 series finds them absolutely fine so far on his October/November 2006 built E91 335i.

bnj, when was your car built?

October 2006 e92 335i

epiphone3 · 03-26-2007, 11:18 AM

Quote:

Originally Posted by agh!

In this RFT's are OK / not OK debate, lets throw into the ring the fact that September 2006 build dates onwards have a different part number for struts than pre-Sept 2006 cars. This could mean that is is not an E92 vs. E90/E91 issues at all, it could be down to new improved suspension set up.
An E91 owner I know who historically hates RFt's on 1 and 5 series finds them absolutely fine so far on his October/November 2006 built E91 335i.

bnj, when was your car built?

I have a December 2005 build date and I thought that my RFTs were perfectly fine for a while too. Then they wore a bit and started to suck. I only have 13,000 km on my Summer Potenzas and they are pretty poopy.

KevinC · 03-26-2007, 11:52 AM

Quote:

Originally Posted by agh!

In this RFT's are OK / not OK debate, lets throw into the ring the fact that September 2006 build dates onwards have a different part number for struts than pre-Sept 2006 cars.

They switched suppliers - from (I think) Boge/Sachs to (I'm sure) Bilstein.

NOTHING to do with the runflat tires sucking hind tit.

bnj · 03-27-2007, 06:37 AM

Quote:

Originally Posted by Richwm

Buy PS-II over stock RFT's

higher cornering limits (.95 g's stock .98 with PS-II's)

Nobody has been correcting the false info in this thread. Just an example,
I hope that everyone knows that in reality e.g. 335i e92 & stock Potenza runflats does 1.15 g. Where do the people get these "facts"?

agh! · 03-27-2007, 07:05 AM

Quote:

Originally Posted by KevinC

They switched suppliers - from (I think) Boge/Sachs to (I'm sure) Bilstein.

NOTHING to do with the runflat tires sucking hind tit.

Fair comment. The ride seems to be better on the newer struts / shocks, the other rft woe's still may reveal themselves with 8K+ miles of wear and / or colder weather.

Richwm · 03-27-2007, 10:08 AM

Quote:

Originally Posted by bnj

Nobody has been correcting the false info in this thread. Just an example,
I hope that everyone knows that in reality e.g. 335i e92 & stock Potenza runflats does 1.15 g. Where do the people get these "facts"?

1.15 g no way its a 3er not a Porche or a Z06 Vet. Car and driver only got .88 g on a 328 sport not even a stock M3 will do 1.15 g.

bnj · 03-27-2007, 10:12 AM

Quote:

Originally Posted by Richwm

1.15 g no way its a 3er not a Porche or a Z06 Vet. Car and driver only got .88 g on a 328 sport not even a stock M3 will do 1.15 g.

Yeah, but stock runflats on e92 335i are so good that it's much better than M3 with bigger rims & wider non-runflat lowprofile tires + the praised M3 suspension.

Josephkao · 03-16-2008, 10:32 PM

I check on Tirerack, size 225/40/18 RFT and non RFT weigh actually the same at 25 lbs. Go on their site and check it yourself.

Richwm · 03-16-2008, 11:49 PM

Quote:

Originally Posted by Josephkao

I check on Tirerack, size 225/40/18 RFT and non RFT weigh actually the same at 25 lbs. Go on their site and check it yourself.

True but PS-2's are only 21 lbs.

03-23-2007, 03:29 PM	#47
N1 Second Lieutenant 15 Rep 272 Posts Drives: BMW 320d M Join Date: Feb 2006 Location: EU iTrader: (0)	BMW Run-Flat Tires Video http://www.metacafe.com/watch/333266...un_flat_tires/ only for drivers with hands.
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03-26-2007, 07:18 AM	#48
agh! Private First Class 1 Rep 112 Posts Drives: E91 320d SE Join Date: Aug 2006 Location: Hampshire UK iTrader: (0)	In this RFT's are OK / not OK debate, lets throw into the ring the fact that September 2006 build dates onwards have a different part number for struts than pre-Sept 2006 cars. This could mean that is is not an E92 vs. E90/E91 issues at all, it could be down to new improved suspension set up. An E91 owner I know who historically hates RFt's on 1 and 5 series finds them absolutely fine so far on his October/November 2006 built E91 335i. bnj, when was your car built?
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03-16-2008, 10:32 PM	#56
Josephkao Captain 46 Rep 997 Posts Drives: 2008 335i sedan Join Date: Feb 2008 Location: Irvine, CA iTrader: (13)	I check on Tirerack, size 225/40/18 RFT and non RFT weigh actually the same at 25 lbs. Go on their site and check it yourself.
	Appreciate 0 Quote