Best Run Flats

[jonoe30 53]

My little brother needs to replace the RFTs on his E91 Motorsport (staggered 17" alloys). I can see threads from a few years ago saying that Pirelli's were probably the best bet.

Just thought I'd recheck and see if people are still fitting these or if there are newer versions out and opinion has changed.

[m325i 709]

I would not buy RFTs to replace. 

I haven't driven the Pirelli's but at least they sound better that the Potenza.

The Potenza perform pretty well, but the wear rating is very low and the ride is so hard/harsh. 

You can get way better tyres that will last longer, perform better and ride nicer, for cheaper than RFT.

 

 

 

[jonoe30 53]

Yeah I know the arguments against getting them, and if it were me I wouldn't keep them, but to be honest in the nicest possible way he's not the kind of person who's going to fiddle around with a goo pumping solution ("M Mobility" style) on the side of the road, or carry a spare in his boot (I thought we might have been able to fit a space saver in the cavity under the boot, but it's way to small), so have decided to continue down the RFT path.

[m325i 709]

Tire Rack won't ship Pirelli to NZ so your options may be limited. 

[KiwiTT 23]

I am noticing a few times now with this wet weather at 50km/h speeds that I am getting the DTC warning light flashing a few times per day with driving on wet roads.  I don't really feel confident driving them in the wet because of that, so am considering changing my tyres well before the tread depth requirement.

They may still have the original tyres that they were important with from Japan, so I am not sure the age and tyre rubber can 'age' I believe, so having new tyres with more grip might better sooner rather than later.

I still want to go with RFT anyhow, so I have read some reviews and Pirelli or Bridgestone mat be the better option.  And leaning towards Bridgestone as they seem to be more readily available.

http://www.bridgestonetyrecentre.co.nz/tyre/t290/Passenger/

Online reviews seem to indicate that they are quite a poor option.

The Pirelli's seem harder to get ?

Requested a quote from - http://www.tyrepower.co.nz/

 

 

 

 

 

Edited March 12, 2017 by KiwiTT

[Herbmiester 923]

I had Bridgestone RE050 RFT's on my old E60 and while the stiff sidewalls did nothing for ride comfort the car was very composed at speed. 

[Michael. 2313]

Best run flats. Sounds like an oxymoron! 

Just tell him to get decent tyres, and have a spare.

[jonoe30 53]

I forgot to follow up with the outcome... he ended up getting Pirelli P Zero run flats to replace the OEM Bridgestones (which may have been the originals or second set, they were overdue for replacement wear wise)... was about $1650 all up including alignment which I thought was very reasonable (225 front and 265 rear fitment I think).

I've been borrowing the car since December and have done around 5000km on them... they are much more forgiving, more like normal low profile tires, don't tramline like the Bridgestones did and in the recent downpours have been very compliant and not too prone to aquaplaning. Wear seems to be good so far.

[KiwiTT 23]

I have got a quote for Pirelli P Zero - BMW fit for the same price as above - $1650, but I can also get Bridgestone OEM RE0050A RFTs for $1247 (currently 4 tyres for the price of 3) special until 17 March.

Is it worth the extra $400?

 

[Herbmiester 923]

The Re050A has always had a good reputation.

[Matth5 471]

My car came with those Bridgestones and I thought they were awful. Terribly harsh, prone to tram lining, made my arms tired on long drives from all the steering effort needed on bumpy roads.

Grip in the wet was terrible. Wheelspin in 3rd gear on a stock 335i. On my Goodyear Eagls F1s I can only break traction in 1st in the dry and 2nd in the wet - but I have to try, it doesn't happen by accident. 

Maybe on a 325i or lower they would be acceptable for grip. Just not in 19-inch unless you like having your bones shaken.

Edited March 13, 2017 by Matth5

[jonoe30 53]

Aren't the RE050s what they shipped with? Whatever it had on it I found them very harsh... unfortunately all tire/suspension opinions are very subjective... I usually drive an E30 with Toyos which have much bigger side walls so take my opinion with a grain of salt  

Edited March 13, 2017 by jonoe30

[Olaf 3317]

26 minutes ago, Herbmiester said:

The Re050A has always had a good reputation.

I drove some on that 330i that I nearly purchased and thought them average (comparing against RE003 is maybe unfair?); today I drove some on an e60 (245/40R18) and found them good (grippy enough, stiff sidewalls)... on the UK tyre review website, they rate reasonably well.  My interpretation is "appreciated bordering on well regarded".   http://www.tyrereviews.co.uk/Tyre/Bridgestone/Potenza-RE050A.htm

HTH

Edited March 13, 2017 by Olaf

[Matth5 471]

I have driven several thousand km in rental Holden SV6s with the non-runflat version of the tyre and those were perfectly fine. Still not as grippy as the best, but comfortable and suited that car just fine. I think it's those stiff runflat sidewalls that make a major difference. 

[KiwiTT 23]

The other thing I have thought is from what I have read is that the suspension has been calibrated for the RFT stiffer sidewalls.

This is what I read also in the BMW 3 Series development book.

 

 

“Suspension system designed for run-flat tires

Benefit

• Optimum riding comfort

The relatively stiff sidewalls and greater weight of run-flat tires call for specific suspension tuning. On vehicles where both regular and run-flat tires are offered, riding comfort may be somewhat compromised with the run-flats. Because the new 3 Series is engineered “from the ground up” for run-flat tires, its suspension is optimally calibrated for them.  This means that riding comfort is optimum; in other words, the new 3’s ride”

 

So I may notice other issues if I change from the OEM setup.

 

 

330i_Book.pdf

Edited March 13, 2017 by KiwiTT

[jonoe30 53]

I wouldn't worry about the suspension setup especially if you are changing from one type of run flat to the other. Plus all of BMW's marketing around RFTs was designed to sell the idea that they were for better performance and convenience and not that they were a cost saving and economy improving measure (which would have been the main drivers for the switch). I would hazard a guess and say the calibration for RFTs is relatively subtle... slightly different spring and damper rates, as people regularly switch to non-RFT's without issue.

Going back to your original post KiwiTT, what tires does the vehicle have on it now? Apart from the DTC warning activating (it's hard to say whether this is happening too often without driving with you, though at 50km/h I'd expect you'd have to be turning some very tight corners or braking very sharply on slippery surfaces to activate it) do you have any other issues with them?

Edited March 13, 2017 by jonoe30

[jonoe30 53]

14 minutes ago, 3pedals said:

You can use a very simple rule  for tyre age:  0-4 years good to use on a road wheel 4-6 years  marginal on a road wheel - better as a spare,  post 6 years ditch them.

Sage advice

[jonoe30 53]

22 minutes ago, 3pedals said:

P.S also check the wear figure  anything over 500 won't stick in the wet

100-250 is a sticky tyre

250-400 is a touring tyre

500 plus is something to stop the chassis dragging on the ground.

 

FYI - according to Tire Rack the Bridgstones are 140 and the Pirelli's are 400
https://www.tirerack.com/tires/tires.jsp?tireMake=Pirelli&tireModel=P+Zero+Nero+All+Season+Run+Flat

https://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE050A+RFT
 

Some additional info for those interested: https://en.wikipedia.org/wiki/Uniform_Tire_Quality_Grading

Edited March 13, 2017 by jonoe30

[E30 325i Rag-Top 2956]

Going back to the original question posed, what are the best run-flats, whilst I won't suggest a specific brand as a lot of the decision is down to personal taste and driving style, I would just emphasize the fact that the design(s) used in run-flats have been developed over the years and the latest "generation" of tyres are significantly better in regards to the problems most associate with run flats. I am not 100% on how things have changed, or if you can even still buy the older generations, but would suggest that your brother really only look at the latest generation IF they can be fitted on the E91. It's been a while since I drove and E91 but I can't remember the ride being overly harsh even with 19's and M-Sport suspension on the RFTs, and pretty sure they were Bridgstones.

Of the tyres coming from the factory now the Bridgestone is certainly the most widely fitted, but it is hard for me to tell the difference between those and the Contis.

[KiwiTT 23]

I have decided to go with the Bridgestone RE050A RFT as these are the ones that BMW specify, and as I have a 4 year Autosure warranty, and should I develop a suspension fault in those 4 years (the likely life of my tyres - I do about 7,500km a year), they won't have an 'out' because I have non-OEM tyres.

[E30 325i Rag-Top 2956]

Just out of curiosity I checked exactly which Bridgestones are on the current car, answer Potenza S001s. +++would recommend*

* - caveat, only if suitable for your application.

 

 

 

[E30 325i Rag-Top 2956]

4 hours ago, KiwiTT said:

I have decided to go with the Bridgestone RE050A RFT as these are the ones that BMW specify.

Interesting, I have never seen a BMW tyre specification include a brand / variety for anything other than the high- performance models, M cars and M140i / M240i, etc.

i can understand your view, those "mechanical insurance" policies look for any thing to avoid paying out.

 

 

[KiwiTT 23]

48 minutes ago, E30 325i Rag-Top said:

Interesting, I have never seen a BMW tyre specification include a brand / variety for anything other than the high- performance models, M cars and M140i / M240i, etc.

As I have the full M-sport package, I suspect this applies; - "The Potenza RE050A II RFT (Run-Flat Tire) is Bridgestone's Max Performance Summer run-flat tire developed exclusively for selected BMW 3 Series cabriolets, coupes and sedans equipped with BMW's optional sport packages. " - https://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE050A+II+RFT

48 minutes ago, E30 325i Rag-Top said:

i can understand your view, those "mechanical insurance" policies look for any thing to avoid paying out.

Yeah ... the way insurance companies work ... if they can find a way to not to pay out, they will.  So not really worth the risk

[Herbmiester 923]

Sad to say Runflats do have to be considered on later BMW's as there is no room for a proper spare. I worry that if I go away on a weekend or worse a holiday weekend I have to rely on my can of tyre goop. BMW efficiency ie less weight because of no extra wheel or tyre does have a downside. Run Flats for some people are sadly a real world requirement. I had two sets of RE 050 RFT's on my E60 the first were old and subjectively hard, a second set felt much better and were only a year or so old. So yes age makes a big difference.

[Matth5 471]

6 hours ago, KiwiTT said:

I have decided to go with the Bridgestone RE050A RFT as these are the ones that BMW specify, and as I have a 4 year Autosure warranty, and should I develop a suspension fault in those 4 years (the likely life of my tyres - I do about 7,500km a year), they won't have an 'out' because I have non-OEM tyres.

Did this issue come from your imagination or did you actually ask Autosure about this? I don't believe they would do this, it would be absurd.

I have had several Autosure claims - they have lost money on me and they have never given me any trouble with claims. 

Use runflats if you feel comfortable with them, no need to come up with silly justifications like that. To be honest, this gives me the impression you worry about unnecessary/minor things.

Edited March 14, 2017 by Matth5