[seanblee]

Just had my ContiSportContact 5Ps fitted Sidewall on the fronts look fine, and the tyres don't look too big for the car, so I'm happy. They're rated as 94Y front / 95Y rear (XL), so I've got them set slightly over the placard pressures for 18" 88Y front / 90Y rear at 2.3f/2.6r, but the fronts still look a bit soft to me. Thinking I might take them up to 2.5f/2.7r and see how that goes. Any thoughts?

Pictures at the weekend when I've had chance to clean the tyre lubricant off the wheels and sidewalls...

[Kongen71]

Interested in your feedback on the Conti SC 5P's. I was considering changing my RFT's to the same. Especially interested knowing if you find the grip and comfort better on this premium prices tyre. Worth the extra money? What did you pay?

[seanblee]

Gave them a try last night at 2.5/2.7. Definitely rides much better than the Bridgestones, and the grip is just superb - booting it out of corners used to have the back end squirming with the old tyres, but with the new ones it just digs in and flies

Decided that 2.7 is about right for the back, but I'm going to try the fronts at 2.4, as they seem to have worn the markings off in the centre but not much at the edges. I'm quite surprised at how comparatively low their 'correct' pressure is compared to the RFTs.

[Kongen71]

Originally Posted by seanblee

Gave them a try last night at 2.5/2.7. Definitely rides much better than the Bridgestones, and the grip is just superb - booting it out of corners used to have the back end squirming with the old tyres, but with the new ones it just digs in and flies

Decided that 2.7 is about right for the back, but I'm going to try the fronts at 2.4, as they seem to have worn the markings off in the centre but not much at the edges. I'm quite surprised at how comparatively low their 'correct' pressure is compared to the RFTs.

Did you get the special "rear axle only" tyres or the "all round fitment" on all four?

[seanblee]

I have the proper 'rear' tyre on the back. It's got an extra solid band around the centre, which probably helps get the power down onto the road better.

Did some more 'spirited' driving over the weekend and I'm delighted with them - masses of grip, more consistent grip over rough roads, slightly quieter and much, much less harsh than the old tyres.

[Kongen71]

Originally Posted by seanblee

I have the proper 'rear' tyre on the back. It's got an extra solid band around the centre, which probably helps get the power down onto the road better.

Did some more 'spirited' driving over the weekend and I'm delighted with them - masses of grip, more consistent grip over rough roads, slightly quieter and much, much less harsh than the old tyres.

Ok - you got me convinced May I ask what you paid for them 18" or 19"?

[seanblee]

Mine are on 18" 189s and came in at £660 fully fitted from event-tyres.co.uk (who, incidently, I also strongly recommend!).

[chiark]

I went from Runflats to Goodyear Eagle F1s on 18s with SE suspension. Much better, less disturbed by ruts in the road on corners/roundabouts etc. Night and day difference.

3000 miles later, I got a puncture on a motorway. A big hole in the tread. Stopped when it was safe to do so, put the can of tyre weld in...

...and watched it fall straight out of the bottom, creating a lovely little pool under the tyre.

I went to one tyre specialist (Alba Tyres in Leeds, on the Gelderd Road) who refused to help, and told me they would not touch the tyres as they would then be liable when I died in a ball of flames. So they sent me, with my 2 year old son, out with a completely flat tyre. For "safety". After telling me all sorts of BS about beads, locking bands, etc.

I still cannot describe the utter contempt I feel for the manager there. Especially after another branch of theirs recommended the very same tyres that I fitted, but weren't as competitive on price.

Another supplier was sympathetic but had no stock.

Kwikfit was the most helpful and BS free. The result? 2 new runflats on my rears.

I would never advise relying on a can of tyre weld from personal experience. Runflats, or a spare tyre in the boot.

Also, are people telling their insurance companies that they've gone from runflats to non-runflats? You might want to have that conversation sooner rather than later... Results will vary on insurer.

[zltm089]

Originally Posted by chris_s1

Well, I changed my RFTs yesterday to Falken 452s as many others have done. Just thought I'd post my experience to add to the debate.

I am running the 19" wheels and the Msport suspension, so for the harshness of the ride, that's about as bad as it gets.

I have VERY mixed opinions after the switch, its not as cut and dry as most comments on here have made out.

Yes, the ride comfort is improved 100%, much smoother ride, when you hit a minor bump in the road it feels like a 'normal' car, not like you have just hit something with the bodywork or the sump.
I share the feeling someone else expressed about being embarrassed to take passengers! That problem is cured completely.
Another side benefit is the rattle in my dash has all but dissapeared as well

BUT.....the feel through the steering wheel is completely gone, it feels like there is 2 inches of jelly between the tyres and the road.
Outright grip is no worse, it hangs on in the corners pretty much as before, it's just that sharpness on initial turn in that has dissapeared.

The feeling through the wheel is so different I was convinced they must have got the pressures wrong, but I checked and they are ok.

Now, I do drive the car quite hard and am used to driving cars to their (or my!) limits. So if you're a motorway commuter, don't think twice about changing.
But - if you love the feel of your setup the way it is now, think twice -

Its not all roses, there is a trade-off for the enthusiastic driver. When it comes time to change tyres again, I'm not sure I'll make the same decision.

All that said, I paid about £520 at Micheldever for all 4 Falkens (2x225/35/19 and 2x265/30/19) so they are so much cheaper its probably worth it for cost alone.

Rgs
Chris

good write up!....got me thinking now...

[m1bjr]

Originally Posted by chiark

I went from Runflats to Goodyear Eagle F1s on 18s with SE suspension.

I would never advise relying on a can of tyre weld from personal experience. Runflats, or a spare tyre in the boot.

Also, are people telling their insurance companies that they've gone from runflats to non-runflats? You might want to have that conversation sooner rather than later... Results will vary on insurer.

Here here.
A very common sense approach.
Someone should ask the formal line from BMW about altering the design away from RFTs.
There may be things you simply do not know.
For example how the car will behave with a front puncture now?
As the car is designed with RFTs from inception, are the steering geomtery and wheel offsets sufficient to not see you in the scenery at 70mph?
Take a 20year old Audi for example. The geo and wheels are designed with just that scenario in mind.
And the designed angles ensure the chassis does not veer toward the blown out tyre.
You don't know , what you don't know

[Oli]

I'm not going to get into a RFT vs standard argument here, but my last 335 had Alpina wheels, and these came as an accessory wheel from BMW for the E90 series, with standard tyres, not RFTs.

I also agree about the spare wheel scenario, but Ive never had a blow out(touch wood), and if you have a blow out with either a RFT or a standard tyre, the distance you can travel is minimal, and you are more like to find stock of a normal tyre.

And please remember the 320ED comes with non RFTs now, and this has SE suspension, so the suspension is obviously designed to work with both tyres, that and the M3's come with standard tyres.

Ive made my decision, and I'm not trying to sway anyone else's, but for me NON RFT every time. We all have different views on this subject, and I think in fairness, no one is categorically right or wrong, but we just make the decision that best suits our situation.

[m1bjr]

Originally Posted by Oli

I'm not going to get into a RFT vs standard argument here, but my last 335 had Alpina wheels, and these came as an accessory wheel from BMW for the E90 series, with standard tyres, not RFTs.

I also agree about the spare wheel scenario, but Ive never had a blow out(touch wood), and if you have a blow out with either a RFT or a standard tyre, the distance you can travel is minimal, and you are more like to find stock of a normal tyre.

And please remember the 320ED comes with non RFTs now, and this has SE suspension, so the suspension is obviously designed to work with both tyres, that and the M3's come with standard tyres.

Ive made my decision, and I'm not trying to sway anyone else's, but for me NON RFT every time. We all have different views on this subject, and I think in fairness, no one is categorically right or wrong, but we just make the decision that best suits our situation.

Good intel, thanks.
The only thing that tells almost the whole story though is the geometry setup data (KDS?) for each setup, including offsets etc.
That would be quite telling, not the full picture, but would be a good guide.
Also, that 320 you mention, does it have the same alloy wheels but with different tyres?

[Oli]

No the 320ED has 16" alloys, as they are more aerodynamic, and help to keep the emissions at 109g/km.

[HighlandPete]

Originally Posted by m1bjr

Good intel, thanks.
The only thing that tells almost the whole story though is the geometry setup data (KDS?) for each setup, including offsets etc.
That would be quite telling, not the full picture, but would be a good guide.
Also, that 320 you mention, does it have the same alloy wheels but with different tyres?

We get very complex, from BMW's own strange specs. Take the 320 ES, run-flats and conventional tyres. Rims 7x16" with ET 31 & 34 for both tyre types, from how I read the spec sheets, for front wheels. Also 8x17" with run-flats and ET 34. 7" and 8" rim widths with the same ET????

So no fixed 'figure' for offset as such. Let alone 'fixing' key geometry.

The E60 specs were so different for a car which 'could have' RFTs or not, clearly told me if the user can just play around with wheel options, from base non run-flats, to run-flats and then bigger rims without run-flats again, the suspension was being compromised all ways. So any rigid stance was flawed by BMW's own behaviour. So what wheel/tyre is each chassis 'really' designed for. Which wheel size are the safest???

Let alone the fact that as soon as any major 'approved' tuner gets a BMW, they remove the RFTs.

BTW, BMW themselves will not say it is dangerous, they will obviously recommend RFTs. I have debated it enough with them.

HighlandPete

[F31-340i]

Originally Posted by chiark

Also, are people telling their insurance companies that they've gone from runflats to non-runflats? You might want to have that conversation sooner rather than later... Results will vary on insurer.

Yes. No problem, no charge.

As stated above, the offsets and wheel fits vary lots between the various 3ers anyway, and they are now coming out of the factory with normal tyres, so there is no safety or handling issue with using normal tyres. BMW alloys are not specifically designed for RFTs either - the RFTs are designed to fit normal wheels.

[doughboy]

Originally Posted by m1bjr

And the designed angles ensure the chassis does not veer toward the blown out tyre.
You don't know , what you don't know

But we do know what we do know....

ES models have always had RFTs as a cost option and if you don't buy them you get exactly the same car.

Same suspension
Same bushings
Same wheel sizes
Same steering rack

And the exact same geometry

Look on a KDS or Hunter alignment data sheet and all E90/1/2/3 have the exact same geomtery.

I've had 2 alignments and the dataset was simply "3 series E9x 2005 on" that's the lot.

How can anyone say its 'mad' to rely on tyre weld when tens of thousands of 'sensible' fords, vauxhall's, toyota's and honda's et al do just that - no spare and no runflats.

Don't believe the (RFT) hype.

[m@rk]

So I am still happy with the switch however I read something today that was really telling.

Up to now, everybody has told me that RTF have a much stiffer sidewall and it is this that impacts the over all ride.

The argument is that if you move from RFT to Non RFT, the sidewall is softer and hence the ride is impacted and becomes too soft.

So I was reading about the new 3rd Generation Bridgestone run flats and they make a big deal about how they are only 5% stiffer than a normal non RFT much less than current RFT technology!

So if all the arguments for RTF are true then does this mean the new 3rd generation run flats from Bridgestone are going to:

Be Dangerous?

Ruin the handling?

Invalidate your insurance?

Spoil the ride?

Not be in keeping with the car?






What do you think?

Nuff said

[m1bjr]

Originally Posted by m@rk

What do you think?

I think that at autobahn velocity with the family aboard, I would prefer to be on RFTs when a sudden deflation occurs.

I have seen a blow out first hand and only last year saw a van lose a front on the opposite carriageway, not pretty.

You have to see it to believe it, and it will change your perspective on safety.

[m@rk]

Originally Posted by m1bjr

I think that at autobahn velocity with the family aboard, I would prefer to be on RFTs when a sudden deflation occurs.

I have seen a blow out first hand and only last year saw a van lose a front on the opposite carriageway, not pretty.

You have to see it to believe it, and it will change your perspective on safety.

A blow out is very different to a puncture and a run flat tyre will not make much difference.

[Kongen71]

During a trip back from Germany I had a flat RFT and obviously could't drive all the way back to Belgium. I contacted BMW but they couldn't help me and referred me to someone else. Limited RFT's in stock and not my size. Same story from the next two I contacted. Many hours later I finally found the right tyre and was presented with a €370 bill. A couple of months later I drove into a pot hole on he highway. Result -> a 3-4cm piece of metal from the RFT through the sidewall -> new tyre again. That was on my previous E91. Now on my 3 month old E92 both Bridgestone RFT's on the right side bended in probably from driving on the "nice" belgium highways. RFT's be gone!!!

[HighlandPete]

I think we need to get a perspective on the RFT issues.

Millions of cars running around on non run-flats don't make them all unsafe, as if only RFTs are the 'safe' tyre.

Blowouts are a very smaller percentage of tyre failures, and as said before, most blowouts are caused by poor tyre maintenance and low/wrong pressures for high speed driving. Most of us don't drive in the highest risk category, of autobahn high speeds.

Also the differences in tyre performance are not as great as we sometimes read, it is all much more subtle, if we are objective about it.

The fact that some drivers will make the change to tyre 'x', as others have and the reports vary from "hardly notice the change" to "the car is so soft, I'm putting RFTs back on". Sorry, but that same tyre change doesn't have that spread of difference. We feel things differently, such aspects as suspension frequencies and head toss are felt in a different way by different folks.

True the differences can be clearly felt at the seat of the pants, but if we are running the correct pressures for any suitable tyre, the handling is not messed up. Even choosing a RFT, or non run-flat can have different characteristics, side wall stiffness, lateral stiffness, grip, slip angles, etc., so we will be modifying the feel of a car when we move to a different tyre anyway.

I've had the experience of running two 17" wheel sets, one RFTs, the other set, two brands of non run-flats. To me the biggest difference is, the car is far more settled on the non run-flats, totally predictable and fluid in the drive. Whereas the RFT in the same conditions, same sort of temperatures is a tyre that is so unpredictable and full of surprises as you drive. Plus the jarring and jitters from the inability to assist the suspension to cushion road flaws.

I have swapped the wheel sets several times and clearly discern that the RFTS amplify road imperfections in a lot of circumstances and conditions, rather than allow the car to feel planted and secure.

The normal rubber allows the fastest and safest drive, the car may feel a bit softer, (personally I like that, as it allows better and more pure communication to the road), but not the unpredictable 'on the edge' stuff of RFTs, which easily causes loss of communication to the driver.

And we wonder why M-cars have normal tyres? If any car should have the RFT for safety it is the M-car... but BMW's M-division don't seem to think so.

HighlandPete

[chiark]

Agreed, it's horses for courses and no single answer is right or wrong. All I know is that I've had 3 punctures in my life: one in my e46 330D, when I had a spare, one in my E91 330i with runflats at 70mph on a ringroad, and one in that car when I had standard tyres and a can of tyre weld.

How unlucky can one chap be?

the only puncture that caused an issue was with the non-runflats and tyre weld.

Agreed there is a *lot* of BS talked about putting non-rfts on: when the chap at Alba started talking about different fitments/depths/general scaremongering I didn't have the info at hand to tell him to shut up . I am still scarred by his approach of sending me out with a flat tyre "for safety".

I preferred the handling on the Eagle F1s, but for me the risk of being stranded with family in the car greatly outweighs the benefits. I also think I was deeply unlucky that tyre weld wouldn't work when I needed it to.

My insurance company didn't care, but some do...

Interesting debate. My point in posting was to ensure people consider potential downsides, not to say "you're wrong, I'm right"

Whereas the RFT in the same conditions, same sort of temperatures is a tyre that is so unpredictable and full of surprises as you drive. Plus the jarring and jitters from the inability to assist the suspension to cushion road flaws

I know exactly what you mean, but I think the ones I have (Bridgestone re050 rfts) are jittery, jumpy but they are predictable once you know them. The first time I hit a ridge in the road on a roundabout was 'surprising'

Interesting debate!