[roofer]

...For P/Zero rosso, 255/35 rears, 225/40 fronts.

Ride quality is transformed, turn in is crisp.

I will never buy a Runflat shod car again

 

[Brava]

I will never buy a Runflat shod car again

The same was said at the time of four wheel brakes, disc brakes, radial tires, ABS, etc...

 

[roofer]

I will never buy a Runflat shod car again

The same was said at the time of four wheel brakes, disc brakes, radial tires, ABS, etc...

I doubt it, they were improvments.

 

[Brava]

I will never buy a Runflat shod car again

The same was said at the time of four wheel brakes, disc brakes, radial tires, ABS, etc...

I doubt it, they were improvments.

People did say it at the time. Perhaps not everyone but some people.

 

[gtfire]

Brava,
Yes BRAVA it was said, but as I have said on these pages before I am not willing and I am unhappy at being the test pilot.
I would love a quality RFT but they do not exist at this moment in time.

 

[preppeller]

So in loosing the runflats, are you getting some tyre weild and a compressor just in case you get a puncture? Also, does it bugger up the flat tyre indicator on the onboard computer?

I'd like to get rid of them too but need to know the alternatives.

 

[mrash]

i dont have an issue with the runflat ride quality, i did however come from driving an Alfa!!

 

[ghibbett]

preppeller

I will be looking to junk mine soon too.....BUT, try finding non-RFTs in 130iM sizes..... As i've posted several times before, I cannot find any. And nobody has yet come back to me with a viable suggestion.

Anyone out there with a 130iM on non-RFTs????

 

[weasley]

Isn't there a requirement to carry tyre replacement/repair with you? For the BMW it's not needed as you can limp home on the RFT. My RX-8 had a tyre-fix system and no spare. If you junk the RFT then surely you must carry some kind of emergency equipment?

 

[preppeller]

ghibbett, I have used

http://www.mytyres.co.uk

in the past. They deliver and are reliable.

They have 225/40/18 and 205/45/18 in considerable stock with many brands to choose from. Make sure to pick "summer tyres" else it comes back with no search results.

EDIT:
SCRAP THAT.... the 205/45 are only runflat on there. thats a bit of rubbish!

 

[preppeller]

roofer, I notice you went for wider tires but with a profile which kept the rolling radius within 1%. Do the wider tyres fit on the standard bmw 18" rims? because mytyres have plenty of those sizes in stock.

 

[preppeller]

Ok, sorry to be spamming 3 posts in a row, but I wanted to get to the bottom of what you can get away with on the standard BMW M Sport 7.5x18 Front and 8x18 Rear rims.

using

http://www.carbibles.com/tyre_bible.html

which has lots of calculators on there, I have gotten to the following conclusion:

The best tyre sizes which are in stock in plenty at mytyres (with good brand names and not run flats, fit comfortably on the current rim sizes and only change the speedo by -0.7% (well within boundries ie 70mph on the speedo is actually 69.51mph) are.... *drumroll*

225/40x18 on the front and 245/35x18 on the rear.

 

[roofer]

roofer, I notice you went for wider tires but with a profile which kept the rolling radius within 1%. Do the wider tyres fit on the standard bmw 18" rims? because mytyres have plenty of those sizes in stock.

I chose these sizes because i'm getting a set of Alpina Dynamics in 8"/8.5". You can fit a 255 from an 8" upwards rim

Tyre pressure monitor works fine, and i kept the M mobility system from my M5.

They're scrubbed in now, it sticks like a limpet 8)

BMWCAR magazine have fitted 225/40/18 all round, and report good things

 

[megansdad]

OK MY TUPPENCE WORTH.
I absolutely hate RUN FLATS ,i think they spoil the I Series. They do spoil the ride quality, especially on these roads here in N.Ireland.

I have just turned 7,000miles on mine and the front ones have about another 2,000 left if i am lucky.
Today i have just had my first flat,thanks to a nail. my Tyre center Repaired it although they did say they should,t but i brow beat them into doing it.(they plugged it).

I would replace the lot of them but my BMW Dealer states Replace them and lose your 3 YEAR Warranty, so i am dammed if i do and dammed if i don,t.Not much of a choice really.Looks like i am stuck with Run Flats.

 

[weasley]

Also, does it bugger up the flat tyre indicator on the onboard computer?

Tyre pressure monitor works fine

I was under the impression that the tyre deflation detection didn't measure pressure but monitored the rotational speed of all four wheels. When a tyre deflates (even a RFT) the overall radius decreases, so the rotational speed increases - the ECU sees this and interprets it as a flat tyre. Hence the need to re-initialise the system every time you change tyres, or (strictly speaking) top up tyre pressures.

So, in summary, it should work perfectly well with a non-RFT (in fact maybe even better!).

 

[Ikki]

weasley,

It's not illegal to run without a spare or any way of fixing a puncture. It is illegal to have a spare that is defective or below minimum tread depth. :roll:

 

[roofer]

So, in summary, it should work perfectly well with a non-RFT

That it does 8)

Had it round the lanes tonight....the car is transformed.

No rear skipping out mid bend ridges.
No nanny light blinking every two seconds, and you can feel the compliance in the tyres, which makes the information they give much more accurate 8)

Launching it off the line now just see's it accelerate, insead of having the DTC cut in......now i know why the M division won't specify them.

 

[130girl]

...For P/Zero rosso, 255/35 rears, 225/40 fronts.

Ride quality is transformed, turn in is crisp.

I will never buy a Runflat shod car again

I'm jealous roofer- my RFT are too new to change but will certainly be considering this option later. Can you tell us whether you needed to modify your guards to make the new tires fit? Especially the rear- the OEM 225 is already pretty tight??? Any rub on big bumps with 255?

Any pics? The rear view must look awesome!

130girl

 

[roofer]

Any pics? The rear view must look awesome

Of course

Clearance to shock

Outer arch clearance, this pic shows the car 'loaded', as the other side is on the kerb

I have about 60 kilos of work stuff in the boot as well, no rubbing/fouling issues at all, hth

 

[ghibbett]

The best tyre sizes which are in stock in plenty at mytyres (with good brand names and not run flats, fit comfortably on the current rim sizes and only change the speedo by -0.7% (well within boundries ie 70mph on the speedo is actually 69.51mph) are.... *drumroll*

225/40x18 on the front and 245/35x18 on the rear.

Hi Preppeller,

Have you found decent *matching* tyres over both sizes?

Cheers,