Better runflats than the Potenzas?

A

Any1else

Member
I know there are loads of posts about ditching the runflats (read loads) but i just wanted to check a thing or two with those in the know.

I bought a 3.0 last month and it has the Potenzas on it and it just feels a bit skittish and doesnt inspire confidence. I am thinking of changing them but im not convinced about the non-runflats. Have read about suspension set up for the rfs, spare wheel, tyre goo etc etc. I was wondering if the modern runflats would give a better ride than the Bridgestones. The reviews on the Goodyear Eagle F1 AS2 (which are runflat tyres) seem very positive. Does anyone have experience of moving to a better runflat rather than ditching them altogether?
 
Ditch them altogether you won't regret it.

If you won't go away from run flats I believe the new ones are meant to be better than previous generation ones I.e Bridgestone re 50a's etc

Good luck
 
What you really need to think about is when was the last time you actually had a puncture that caused a flat tyre and would have left you stranded if it wasn't changed?

Over 25 years of driving I've had 3. All on my previous Z4 and all on runflat tyres, all within a week or two.

Ditch the runflats and get normal tyres. The car will be great to drive.

The Goodyear Eagle F1 Asymmetric 2 were available in Non Runflat and Runflat versions.

These are being replaced with Goodyear Eagle F1 Asymmetric 3.

So you could be in a position that you get a puncture on a runflat and have to change both drivers and passenger side tyres if they Goodyear Eagle F1 Asymmetric 2 Runflats are not available. If you get a puncture that is.
 
Run flats are fine......on billiard table smooth German Autobahns and absolutely nowhere else !
In 33 years of driving I have had 2 punctures !
Fit decent quality non-run flats, carry tyre 'goo' and an inflator in the boot and just in case get some AA Relay cover.
To experience the full potential of the Z4 you MUST do this !
 
Consensus is to go to non-runflats I see :p

Goodyear Eagle F1 As 2 seem to get good reviews so would probably opt for them. Few questions on that front then :-

My existing Potenzas are 225/40/R18 88W on the front and 255/35/R18 90W on the rear. I assume that I get the same profiles but what about the load index? Do I get XL loads? Do they differ front to back? What about pressures? I know its loads of questions but this is the best place to get advice.
 
Any1else said:
Consensus is to go to non-runflats I see :p

Goodyear Eagle F1 As 2 seem to get good reviews so would probably opt for them. Few questions on that front then :-

My existing Potenzas are 225/40/R18 88W on the front and 255/35/R18 90W on the rear. I assume that I get the same profiles but what about the load index? Do I get XL loads? Do they differ front to back? What about pressures? I know its loads of questions but this is the best place to get advice.
Click to expand...
As long as you get the right load ratings and an XL tyre you will be fine.
Tyre pressures are also very important and if you have sports suspension you should run (in my opinion) the BMW advised tyre pressures as similar to runflats.
The stiffness of the side wall has a direct correlation with the suspension geometry.
 
Zeld4 said:
Any1else said:
Consensus is to go to non-runflats I see :p

Goodyear Eagle F1 As 2 seem to get good reviews so would probably opt for them. Few questions on that front then :-

My existing Potenzas are 225/40/R18 88W on the front and 255/35/R18 90W on the rear. I assume that I get the same profiles but what about the load index? Do I get XL loads? Do they differ front to back? What about pressures? I know its loads of questions but this is the best place to get advice.
Click to expand...
As long as you get the right load ratings and an XL tyre you will be fine.
Tyre pressures are also very important and if you have sports suspension you should run (in my opinion) the BMW advised tyre pressures as similar to runflats.
The stiffness of the side wall has a direct correlation with the suspension geometry.
Click to expand...

Although there is a a different school of thought that, popular with a lot of folks on here including myself, when you move to non runflats you should change your pressure to M spec of F30 & R 32. I run these pressures on my 3.0i and have been fine as have many others who have been running it for years. It wont effect the cars suspension geometry, the tyres act as an additional dampener more than anything and on newer BMW's where they offer both runflats and a non runflat option from the factory the suspension geometry setting don't change depending on tyre choice, they remain the same.
I personally believe the higher pressures with runflats is really about protect their sidewalls. Remember you are only suppose to run for a max of 50 miles on an under-inflated or punctured runflat tyre. Any further than this and the tyre is done for as the tyres sidewall structure is compromised. This is also why the extra stiff sidewalls of runflats need higher pressures, so they don't flex in normal use on the road (as a normal tyre is designed to) the higher pressures prevent them from flexing and damaging/wearing the sidewalls prematurely. This why runflat versions of the same tyre always seem to have poor handling, be noisier and generally all round unpleasant when compared to their normal sibling.
 
I used to run 33/34 Psi front and 35/36 Psi rear on my zed running non run flats, I found this was best after trying some different configurations :)
 
I guess I will be the one lonely voice in support of RFTs. I have had my Zed from new since 2004, obviously came with the rubbish Bridgestone Potenza RFTs, and the lack of road feel and grip were my main issues with the car when I first bought her. Most of my mods over the years have been aimed at improving road feel, and therefore confidence when driving. I wanted to keep RFTs as I just didn't like the idea of having a scary blowout at speed again (happened in my Mum's Volvo 440 with me driving in the fast lane of the M1) and then being stranded waiting for the RAC/AA to turn up (sorry, I'm embarrassed to admit I've never changed a tyre/wheel in my life, and didn't do it on that occasion in the dark on the hard shoulder of the M1 at that time). After 2 sets of Potenza's I changed to Pirelli Euphoria RFTs - they weren't a night and day improvement over the Potenza's in the dry, but there was definitely improved steering feedback/road feel in the dry, and their wet weather handling was vastly improved over the rubbish Potenza's. 3 years ago (I think it was), I changed to the new Pirelli P-Zero RFTs and suddenly there was the night and day vastly improved dry weather also performance that I was looking for (compared to the awful Potenza's, although I do think the wet weather handling of the P-Zero's are not quite as good as the Euphoria's), and I haven't looked back since.
I admit I have never driven a Z4 with non-RFT tyres, so they may well handle and have better steering feel than my Zed despite all my mods and the P-Zero RFTs, so I can only comment upon the changed and vastly improved handling of my own car through the 3 different RFT's I have used over the years, but given that I personally did not want to move away from RFTs and neither does the initiator of this thread, I thought I should speak up and offer Any1else a different perspective from someone who actually likes his RFTs - as unpopular an opinion as it may be :)
 
Thanks dipster. Good post. That is what I was looking for. I am not overly precious about the runflats but would like to have a measured view as to whether the newer style were better than the OEMs. From what you are saying this seems to be the case so if I was inclined to stick with the runflats, there may be some hope that the newer style will give a better ride.
 
I had Bridgestone run flats on my zed & they ruined the driving pleasure. Got non runflats on my winter wheels & the difference is massive. Just fitted non rft's Michelin pss to my summer wheels the other day,can't wait to get them back on when weather improves.
Our 640d has Dunlop rft's fitted & 20" too & to be fair they are ok. Massive improvement over the Bridgestone.
 
I think, Any1else, from reading KERMIT1970's post that it is likely that all the modern RFTs are a vast improvement over the rubbish (and in the wet, lethal!) Potenza's. The only thing I would add from my own perspective is in response to your comment that you hoped the newer RFTs would 'give a better ride'. I should mention that my Zed still has an extremely firm (read 'hard') ride, despite my P-Zero's. That may have something to do with my mods/setup though. But that's fine with me - I actually like the firm/hard ride, and just do my best to avoid broken bits of road or obviously bumpy road (if I can). The benefits of my P-Zero's, aside from the safety benefit and convenience of having a RFT fitted, is the wonderful dry weather steering feedback/road feel and the confidence it gives me to push when I want to, and the vastly improved wet weather handling over the Potenza's (albeit not quite as good as the Euphoria's before them). The ride quality itself though is probably nearly as hard and non-compliant as with the original Potenza's. But as I said, I'm totally fine with that as that's not what I was trying to achieve with my set up/mods. It was all about getting rid of the vague steering feel that my Zed had out of the box, and this I (eventually) achieved, and I think the P-Zero's were a significant component of that. Thank goodness :)
 
Think it more down to the manufacturer ! My Bridgestone's were from a 2014 z4 & are terrible :thumbsdown:
 
Another thing is that im not sure of the quality of the roads in NZ (I see dipser is based in NZ) so that may make Run Flats feel better or worse.

Run Flats can still get blow outs too, just because they are Run Flats doesn't make them any safer than normal tyres! I have read some horror sorties of Run Flat blow outs on other forums.

Only you can decide what you should do OP but I wish you the best and let us know how you get on :)
 
I changed from the Potenza to Pirelli run flats on my Coupe and the difference was massive.

Very little tramlining with the Pirelli but they cost nearly £900 fitted :o

Only reason id stick with RFT's is if I was still under BMW warranty
 
Here is my humble opinion on run-flats:
-I drove 2 Z4s with 18" run-flats during my search. They both felt horrendously uncomfortable.
-This made me go for a Zed with 16" wheels, as my main aim was comfortable long distance driving around the country.
-When I first drove the car with 16" wheels, I couldn't believe the difference. It was so much more comfortable, which made me think the tires must be non-run-flats.
-I was surprised to see that the tires were actually Bridgestone Potenza RE50 run-flats. :o
-I know 16" is considered ugly and an enthusiasts forum is not the greatest place to make a case for 16" wheels. But they are noticeably more comfortable then the 18" ones. Even with the run-flats on.

-I had an occasion when I had two punctures at the same time (must have driven over something nasty).
-Run-flats got me from London to Wokingham (about an hour drive) at around 55-60mph driving. :thumbsup:

Bottom line: If you are like me and don't care about the looks as much, run-flats are fine on 16" wheels. (I know this does not really help with your original question :P )
 
Hi hopz121. I actually only moved to NZ in August 2015 (the Zed didn't get here till mid-September - thank goodness as the rental from Hertz was rubbish!) so I ran the Zed in the UK from 2004 to the time of my departure, and my observations of my RFTs are really based upon my time in the UK. The quality of the roads in NZ vary widely - in the rural town I'm working in they aren't very good, but in the city they are lovely and smooth. I obviously prefer the latter roads, but the Zed is still fine everywhere, and not all that different feeling from the UK.
Thank you for the point about getting blowouts on RFTs - I genuinely did not know that could happen. When it happened in my Mum's Volvo it was quite a scary experience, and I had hoped (or assumed) that a blowout would not happen on a runflat. Oh well. Still love my P-Zero's though and would highly recommend them for anyone who wished to stay on RFTs. Interesting point from KERMIT1970 that the modern Potenza's are still terrible and that really surprises me - it never occurred to me to move back to Bridgestone as their RFTs were so terrible the first couple of years I had the Zed, and I have obviously become a Pirelli fan since, but I guess I just assumed the modern Bridgestone RFTs would have improved in the 10 or so years since their introduction. Perhaps the take home point for owners wishing to remain on RFTs is to simply avoid Bridgestone and only look at other manufacturer's takes on runflat technology.
 
Nah its not under warranty its just a big leap to replace all the tyres when the ones that were on the car when I got it have 5-6mm tread. It seems to get the most from the car it is non runflats with goo but space is limited in the car and I have the carver amp in the boot where everyone sticks the compressor. The car is a weekender, and I have just bought it so I might tolerate these tyres for a while and explore my options when they hace less tread. Still like the idea of runflats but I want the driving experience too. I know ... I know .... want want want.
 
OK, bulge in the side wall of one of the front and an MOT due next week hastened my decision. I decided to stay with the runflats but ditched the Bridgestones. Went for two Michelin Pilot Sports ZP on the front and the difference is just staggering. No tramlining, no snatch, no wandering and very little concentration and effort required to keep the car straight. Car feels planted and much more enjoyable to drive. I would swear that I had standard (non runflat) tyres on the car. Such a massive difference.
 
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