[HighlandPete]

As an engineer I was very interested in the RFT approach when BMW seriously brought the concept back to life, after an earlier attempt by others, of the Dunlop Dunova failed.

The concept is brilliant, the safety aspects are sound. It is just the execution of the concept is so flawed. They just don't work on the roads I drive day to day. I personally would have sold my BMW, if I couldn't have swapped back to conventional tyres (after being a BMW customer for many years) and gone back either to an older model, or to another marque.

The Bridgestone G3 does sound much better, I've offered to try a set for Bridgestone, as I've contact with a Bridgestone Field Engineer, but there seems to be a delay. It is still a leap of faith in a new rubber technology, so may have issues ahead anyway.

I've tried a couple of different wheel sizes on the the new F10, hoping to go to an F11 touring, but still feel the RFT influence is still there, to cause less than ideal driving characteristics.

To me other than the sharp turn in, (not too important to many drivers and costs in rapid wear) most driving characteristics are compromised, conflict with what we understand tyres are doing 'in harmony' with the suspension.

HighlandPete

[seanblee]

Finally got round to grabbing some quick photos of the ContiSportContact 5Ps. I'm now running them at 35psi on the front and 38psi on the rear, which is the stock pressure for the Mercedes E350 on the same tyres.

They definitely give a far more compliant ride - you still feel big potholes, but they're much less jarring, and smaller road imperfections are felt much less. In combination with my Koni FSD shocks and standard M-Sport springs, I'm now very happy with the ride quality.

In terms of performance, WOW. They're just superb. I had a chance to try them out in the wet last weekend, and taking corners at speeds that would have the Bridgestones skipping and squirming is now as straightforward as it should be. Pushing on a bit, they have absolute masses of grip, and are capable of putting power down on the road a lot easier than the RFTs. Oddly, my MPG seems to have improved slightly in the same conditions, though my average has dropped because the car's much more pleasant to drive harder now!

Pics below - you can see that the 235 profile on the standard 18x8J Style 189 front alloys looks just fine, as does the 255 profile on the 18x8.5 rears.

[Kongen71]

Thanks for sharing. You got me convinced

[doughboy]

We need some tread pics, not just side walls

[seanblee]

Stolen from Conti's website The rear is the one on the left, with the double centre tread band, and the front is on the right.

[doughboy]

I've seen those shots, it woulde be nice to see the tread pattern in real life though....

[seanblee]

I'll try and grab some shots later.

[RichJ]

are they available for 19's yet?

[Kongen71]

Originally Posted by Rich Jones

are they available for 19's yet?

Yes

Check:

http://www.conti-online.com/generato...t_csc5p_en.pdf

[RichJ]

I saw that but tried a few tyre websites and they are not shown as being available yet, instead the sport contact 3's?

[seanblee]

Event Tyres (http://www.event-tyres.co.uk) list the fronts in 19", but not the rears. They do the fronts in 235/35 R19 and the rears in 265/30 R19 though, so that's a possibility.

[zltm089]

Nice pics!!!...hey we got the same wheels!....

so, looks like for the fronts you can go 235 .....i'm on 225 atm....wonder which one is the "perfect fit" ...

On the TTS its 245 all round....

[Kongen71]

Originally Posted by zltm089

Nice pics!!!...hey we got the same wheels!....

so, looks like for the fronts you can go 235 .....i'm on 225 atm....wonder which one is the "perfect fit" ...

On the TTS its 245 all round....

225 is the "natural" fit but personally I think the 235 looks fine on the rim

[doughboy]

Originally Posted by Kongen71

225 is the "natural" fit but personally I think the 235 looks fine on the rim

I agree, which I why the OE 255 on the 8.5 18" rim is too wide IMO.

Seems odd, a 225 on a 8" rim and a 255 on a 8.5" rim.

30mm tyre width increase for a 12mm rim width increase....

[rup]

After 25k+ have replaced the rear Bridgestone RFT with Falken 452. Much more grip/acceleration from the back now. Maybe partially as replacing old for new but still think the Falkens give much better grip than RFT even if both new. Had new RFT before.
Great value approx half the price of RFT.
Now just have to wait for fronts to wear so i can replace those too
I fully recommend ditching the crappy RFT, what were BMW thinking? How to wreck £40-50k cars with shit tyres?
BTW, some people say not to mix RFT with non RFT, nonsense i say, as long as same tyre across each axle then fine.

[Wh|t3R@bb|t]

I have 452's on mine, and done about 2-3000 miles on em. Love the grip and definate better road manners and ride quality. However, do think they have a distinctive road noise once warn in....but you get used to it and is so worth it over the RFT's

[zltm089]

http://www.kouki.co.uk/utilities/vis...ize-calculator


something useful....255 ...is the maximum on the 18inch wheels...

[Leaforge]

Hello All
Similar to others on this forum I have been surprised how badly my 330d Msport suspension on RFT's copes with the many pot holes on UK roads. To add insult to injury 80 miles from home on the M42 I had a loss of pressure alert so slowed down and carried on to destination in Stratford (10 Miles). Tyre was in a mess. As it was 8.30pm could not get a tyre so had to stay in a hotel until morning.

I have Bridgstones so tried to get a match – no joy none available, waiting for production run. ATS had Conti’s but would not put a single tyre on the car, they wanted £1k+ for 4 tyres they would not even put a pair on the rear. Eventually had to get a 255/35/19 (mine are 255/30/19) on as a get me home alternative.

Now have to make decision!
• Dump the run flats & change size to 255/35/19 all round to get a little more rubber between the rim and the road
• Bridgestone RFT’s if I can find some and upgrade to 255/35/19 to help with the chattering teeth on anything other than a flat road.

Has anyone increased the aspect ratio of tyres on their car, any feedback, suggestion's or experiences would be gratefully received. As car is 5 month old and only done 4000miles or s,o as you can imagine not impressed with this aspect of the car.

Many Thanks

[M3-FAST]

Changing from 30 to 35 profile tyre will add an inch to the overall tyre diameter.

Means at 60mph your speedo will read 62mph

http://www.e90post.com/forums/forumdisplay.php?f=12

A good tool to use when looking at tyre sizes - excellent at calculating offsets and working out how different rolling radius can affect speedo etc...

[doughboy]

Originally Posted by M3-FAST

Changing from 30 to 35 profile tyre will add an inch to the overall tyre diameter.

Means at 60mph your speedo will read 62mph

Wrong way round mate

A larger OD will mean the car is going FASTER than the speedo reads, which is decidedly dodgy.

I.e your speedo reads 30 but you are actually doing 32 for example...

Re the question, don't change up a profile for speedo and odometer error issues, if you go to NON RFTs, of which there are plenty in your size, then the ride quality will be massively improved without going up a profile.

Also be aware of using non OE sizes re your insurance, they may see it as an undeclared 'modification' if you use sizes not on the rating plate come accident time.

[TMP]

Originally Posted by rup

After 25k+ have replaced the rear Bridgestone RFT with Falken 452. Much more grip/acceleration from the back now. Maybe partially as replacing old for new but still think the Falkens give much better grip than RFT even if both new. Had new RFT before.
Great value approx half the price of RFT.
Now just have to wait for fronts to wear so i can replace those too
I fully recommend ditching the crappy RFT, what were BMW thinking? How to wreck £40-50k cars with shit tyres?
BTW, some people say not to mix RFT with non RFT, nonsense i say, as long as same tyre across each axle then fine.

Mate are you running front RFT with rear Non-RFT's?
If you are, I really dont think that's a good idea.......

[rup]

Originally Posted by TMP

Mate are you running front RFT with rear Non-RFT's?
If you are, I really dont think that's a good idea.......

Yes, as have others on this forum and have more grip than when all RFT. Have booted it out of many corners, no problem. Traction comes on much later than it used to. Really dont see a problem.