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[mlai]

Hello,
I am thinking about getting rid of the RE050A RFTs on my 135i vert. The problem is that the stock tire sizes doesn't give me a lot of choices for the fronts.

If I switch the front to 225/40R18 non-rft instead of the 215/40R18 rft, will that affect steering of my 135i too much? My 135i still has stock sport suspension. Haven't got around to switching to BMW performance suspension yet.......

Also, any tire recommendations? PS2? PZero?

Much appreciated.

[desty]

Its been done a million times putting 225/255 or at the limit 235/265 on stock rims, no problem there.

Dunlops Star Spec or Hankook V12 are pretty popular.

[mlai]

Originally Posted by desty

Its been done a million times putting 225/255 or at the limit 235/265 on stock rims, no problem there.

Dunlops Star Spec or Hankook V12 are pretty popular.

Many thanks! Heard good things about the Hankook as well but could go pass the emotional hurdle of getting Korean tires...

How does the Star Spec compare to the RE050A RFT regarding road hold capability?

[moveswiftly]

I know a few people who are running over 400 WHP and have issues griping with the Hankook V12. I recommend the Dunlop Star Spec. That's what I'll be running for my Daily driver / Weekend track tire =)

[mlai]

Bad news. None of the P Zero/PS2/Dunlops have the sizes that I want in stock.....
So my choice down to Bridgestone S001 and PS3 (yikes).

Ended up going with PS3 as I have heard not so good things about S001 wet tractions.......

[VMRWheels]

215 to a 225 wont be a noticeable steering response difference for daily driving. There are a handful of members that swap to this setup all the time. I would suggest a 255 in the back as well to mate with the 225 front.

-Charles@VMRWheels

[Gary@TireRack]

Agreed on sizing.

Check the Conti DW.....all the performance of the PS2 at a lower price.

[mlai]

Originally Posted by Gill@Tirerack.com

Agreed on sizing.

Check the Conti DW.....all the performance of the PS2 at a lower price.

DW not available in Hong Kong Considered 5P but no 225/40R18

[mlai]

Originally Posted by VMRWheels

215 to a 225 wont be a noticeable steering response difference for daily driving. There are a handful of members that swap to this setup all the time. I would suggest a 255 in the back as well to mate with the 225 front.

-Charles@VMRWheels

Thanks. Thought of that as well. Getting 255/35R18 for rear

[MikesBMW]

^ is gas mileage affected much from the wider tires?

[mlai]

Got the PS3 installed today. Boy! Is there a difference! And I haven't really broken in the tires yet (obviously)!

Original OEM tyres: Bridgestone RE050A RFT Front 215/40R18 Rear 245/35R18
Now: Michellin PS3 Front 225/40R18 Rear 255/35R18
Tyre pressure +2Psi vs stock recommendation

1) Ride comfort: Much more compliant. And can feel via steering as well. Enough road feel but not like you are a road construction worker drilling the pathment..... Way easier on the driver (me)

2) Cornering: Haven't done must spirited runs yet. But I definitely feel LESS confident due to increased body roll and MORE understeer than the runflat. I am a bit baffled but maybe the front wheels are over inflated a bit too much, and the tyres have not completely broken in yet.....

3) Acceleration grip: This is the area that I experienced the most improvement over the RE050A RFTs. I live on the hill side, up a long relatively straight stretch of 30Deg inclines with multiple entrances along the incline. At those entrances, I will have up accelerate from practically stand still and merge with uphill traffic already @60-70km. (Yeah wierd. But That's Garden Road in Hong Kong).

The DSC used to flash all the time with the RE050A runflat and I have to really do rolling starts for the wheels to have any reasonably grip to accelerate. DTC doesn't help much either. And with DSC/DTC completely off, the RE050A just spin like crazy without any grip. This does not inspire much confidence to merge with uphill traffics already at speeds....

With the PS3, DSC flashed only twice (at most 3 times). With DTC only, I haven't noticed any significant wheel spin at all! With DSC/DTC complete off, I can feel the wheel spins, rear slipping sideways a tiny bit (fun). Definitely way better than the RE050A RFTs where the wheels just spins and the 135i wasn't going anywhere!

All in all, I am happy so far except for the cornering softness and understeer. But I am willing to give the tires a bit longer to see if there is any improvement after the tyres are properly broken in.....

On a side note: I am looking to replace suspension due to softer non-rft tyres but turns out BMW performance suspensions are not for the vert. Is Bilstein PSS10 or KONI FSD an improvement over the sport suspension on the 135i?

[Top Gon]

Originally Posted by mlai

Many thanks! Heard good things about the Hankook as well but could go pass the emotional hurdle of getting Korean tires...

How does the Star Spec compare to the RE050A RFT regarding road hold capability?

it's a world of difference from those crappy RFT's. I would say the Star Specs in the wet grip better than the RE050A's in the dry !

[desty]

i heard from discounttirediscount that the star specs were discontinued? did they change the model?

[Top Gon]

Originally Posted by desty

i heard from discounttirediscount that the star specs were discontinued? did they change the model?

yeah, Seems that Tire Rack has some kinda monopoly on them or something because they're the only ones that carry them. Even my local tire shop had to order from them when I got mine.

[Paul W 1138]

Originally Posted by mlai

Got the PS3 installed today. Boy! Is there a difference! And I haven't really broken in the tires yet (obviously)!

Original OEM tyres: Bridgestone RE050A RFT Front 215/40R18 Rear 245/35R18
Now: Michellin PS3 Front 225/40R18 Rear 255/35R18
Tyre pressure +2Psi vs stock recommendation

1) Ride comfort: Much more compliant. And can feel via steering as well. Enough road feel but not like you are a road construction worker drilling the pathment..... Way easier on the driver (me)

2) Cornering: Haven't done must spirited runs yet. But I definitely feel LESS confident due to increased body roll and MORE understeer than the runflat. I am a bit baffled but maybe the front wheels are over inflated a bit too much, and the tyres have not completely broken in yet.....

3) Acceleration grip: This is the area that I experienced the most improvement over the RE050A RFTs. I live on the hill side, up a long relatively straight stretch of 30Deg inclines with multiple entrances along the incline. At those entrances, I will have up accelerate from practically stand still and merge with uphill traffic already @60-70km. (Yeah wierd. But That's Garden Road in Hong Kong).

The DSC used to flash all the time with the RE050A runflat and I have to really do rolling starts for the wheels to have any reasonably grip to accelerate. DTC doesn't help much either. And with DSC/DTC completely off, the RE050A just spin like crazy without any grip. This does not inspire much confidence to merge with uphill traffics already at speeds....

With the PS3, DSC flashed only twice (at most 3 times). With DTC only, I haven't noticed any significant wheel spin at all! With DSC/DTC complete off, I can feel the wheel spins, rear slipping sideways a tiny bit (fun). Definitely way better than the RE050A RFTs where the wheels just spins and the 135i wasn't going anywhere!

All in all, I am happy so far except for the cornering softness and understeer. But I am willing to give the tires a bit longer to see if there is any improvement after the tyres are properly broken in.....

On a side note: I am looking to replace suspension due to softer non-rft tyres but turns out BMW performance suspensions are not for the vert. Is Bilstein PSS10 or KONI FSD an improvement over the sport suspension on the 135i?

Thanks for this. If you could please let us know regarding breaking the tires in and the cornering situation, I would be most grateful.

Best,
Paul

[mlai]

3 days and 100km. Adjusted front tire pressure to stock psi and rear to +1 psi.

Noticed an improvement in understeer after reducing front tyres pressure. The 135i still understeer but not as severe. Probably a limit of the tyre without corresponding suspension change.

In terms of acceleration grip for the rear, at +1 psi over stock, the DSC lights doesn't even come on in my tests (uphill traffic merge). With DTC however, there seems to be a bit more wheel spin (no lights flashes though) which baffles me. But then, the tests were not done on the same day and the car still grips well better than the RE050A runcrap (Night and day difference).

Too soon to talk about wear yet, but then, I am not hoping for much. As long as they last longer than PS2s. By the time the PS3 wears out, the PSS should be readily available by then........