[Fundguy1]

Would someone who has had gy please stop being a lemming and try the pss. Then post their conclusions. I can't find one guy who has. As for the m3 guy, are those run flats? The run flats drive hard, wear out faster, cost more, and are generally sucky compared to non rft. If they arent, then compare them same size side by side. If the sizes are different, 18 vs 19, wider, etc, it's not a fair comparison. The Kumho tires are what we would use if you were selling the car and just wanted to slap something cheap on it because the current tires are bald and you don't want to spend much.

[Fundguy1]

And guys, I have no alegance to Michelin. I could care less. I'm just blown away by how you guys could go gy over pss. It's your money. Just trying to give good advice. That's what the forum is for. Maybe post a poll on the tire section of pss vs gy and see what happens.

[Tr1ppy]

I guess you get what you pay for but I'm wondering if it's really worth spending the extra for PSS. They'll be going on my E93 330i so not a huge amount of power/torque but enough to get the car into grip limit territory.

Finally, I changed my fronts from those crappy Bridgestone RFT to conti sport 5p. The size was changed from 225 to 235mm. I found that the steering wants to tramline more and that the car will.find and follow any rut or camber in the road.

Is this behaviour due to increase in tyre width or is it simply the different brand and type of tyre?
Cheers

[djgandy]

Originally Posted by Tr1ppy

Well these handling issues came about as soon as I put the Kumhos on. I went from part worn PS2s in 255/35 size to new Kumho KU39 in 265/30 size.

That's quite a change in dimensions. Were you on 18's before? IMO the rear always felt a little twitchy with such low profile tyres, such is the nature of having barely any flex in the sidewall.

The PSS are grippy but they aren't without problems. The noise they make when I drive over concrete sections of the M25 is ridiculous. The whole car resonates!

[Fundguy1]

Originally Posted by Tr1ppy

I guess you get what you pay for but I'm wondering if it's really worth spending the extra for PSS. They'll be going on my E93 330i so not a huge amount of power/torque but enough to get the car into grip limit territory.

Finally, I changed my fronts from those crappy Bridgestone RFT to conti sport 5p. The size was changed from 225 to 235mm. I found that the steering wants to tramline more and that the car will.find and follow any rut or camber in the road.

Is this behaviour due to increase in tyre width or is it simply the different brand and type of tyre?
Cheers

The tire. Not the width.

[Fundguy1]

Originally Posted by djgandy

That's quite a change in dimensions. Were you on 18's before? IMO the rear always felt a little twitchy with such low profile tyres, such is the nature of having barely any flex in the sidewall.

The PSS are grippy but they aren't without problems. The noise they make when I drive over concrete sections of the M25 is ridiculous. The whole car resonates!

For 18's you want 265/35-18. Going to a 30 is really going short. You're at a 24" outer diameter. You want to be 25" to 26" ideally.

[Tr1ppy]

I'm on 19's. So the factory setting is 255/30 19 (rock hard ride on RFT)

Then I switched to part worn Michelin ps2's at 255/35 19 (felt excellent at all speeds)

And now I have kumho at 265/30 19 (low grip at high speed)

[Tr1ppy]

Originally Posted by Fundguy1

The tire. Not the width.

Ah okay, thanks!

[Fundguy1]

On 19s you want 265/30-19 or ideally if you have the width in the wheels and correct offsets 275/30-19. I have that with 19x9.5 et35 wheels with no rubbing etc.

[Tr1ppy]

Originally Posted by Fundguy1

On 19s you want 265/30-19 or ideally if you have the width in the wheels and correct offsets 275/30-19. I have that with 19x9.5 et35 wheels with no rubbing etc.

Isn't that still too low of a profile? I have run 255/35 before with no issues.
I am on the standard MV4 wheels which I think are 9inch width

[Fundguy1]

No. The outer diameter is what you're worried about. Do you know how profile works?

[Fundguy1]

For 9" wheels you want 255/30-19. 265 or 275 will be to wide for the wheel and pucker.

[Tr1ppy]

Originally Posted by Fundguy1

No. The outer diameter is what you're worried about. Do you know how profile works?

Yep I understand it's a percentage of the width. But as someone posted above, the 30 profile may not offer much sidewall flex and therefore the rear of the car may feel twitchy.
A bit like what I'm experiencing now with the Kumhos, but I think that's largely down to the tyre itself.

[Fundguy1]

Outer diameter for 255/30-19 is 25.1" for 235/35-19 it's 25.5". 265/30-19 it's 25.3" and 275/30-19 it's 25.6"

For 255/35-19 it's 26". Stock is 255/35-18 or 25". You want front and back evenly matched outer diameter as possible. What are you running on the front?

[Fundguy1]

Originally Posted by Tr1ppy

Yep I understand it's a percentage of the width. But as someone posted above, the 30 profile may not offer much sidewall flex and therefore the rear of the car may feel twitchy.
A bit like what I'm experiencing now with the Kumhos, but I think that's largely down to the tyre itself.

It's not the profile, it's the sidewall height. Having front to rear off in outer diameters brings out a whole host of other handling issues way more than twitchy. And twitchy isn't due to sidewall height. It's due to camber, etc. Ride quality drops as sidewall hight drops. And you also loose the sidewall flex in cornering so smaller sidewalks feel tighter more precise and planted during cornering.

[djgandy]

Originally Posted by Tr1ppy

I'm on 19's. So the factory setting is 255/30 19 (rock hard ride on RFT)

Then I switched to part worn Michelin ps2's at 255/35 19 (felt excellent at all speeds)

And now I have kumho at 265/30 19 (low grip at high speed)

Ok. I'm surprised you got 255/35's on without any issues or rubbing. I'd go back to that tyre size if you can. These cars desperately need thicker sidewalls.

[Fundguy1]

The feeling you're having now isn't due to tire or sidewall size, it's due to the tires. May also be that your tires are to wide for your wheels too. 255 is max width for 9" wheels. After that they pucker, wear funny, and flex weird on the sidewalls because the sidewalls aren't perpendicular but at an angle to the ground.

[Fundguy1]

If you have 19s, vs 18's you need to expect a firmer ride, higher tire cost, and heavier wheel tire combo that 18's. If you get similar size outer diameter front to rear, and the tire width correct for the wheel width, you should have no stability issues. You could theoretically go up to 295/30-19 or 305/30-19 rear, 245/35-19 front which is my next combo and have no issues.

[Aragorn30d]

The goodyears are decent tyres, and they tend to place better in reviews than the michelins in the wet too.

The michelins tend to be better in the dry granted, but i've personally found wet weather performance far more important, as your so much closer to the grip limits in normal driving when its wet.

For me, the michelins arent worth the extra money for a small increase in dry grip i cant use, especially when offset against the reduction in wet weather performance.

Goodyear have just released the Asy3 and Michelin the PS4, so it'll be interesting to see how they compare once some decent testing has been done with them.

[Tr1ppy]

Well I run the standard 9 inch wheels so I think the 255/35 should be okay hopefully. I've ran that size before with no issues.

On the front I have 235/35 continental sport 5p which feel great except for a bit of tramlining.

[Aragorn30d]

why not fit the matching contis on the rear? They're also well regarded, though some suggest they wear pretty fast compared with others.

[Tr1ppy]

Originally Posted by Aragorn30d

why not fit the matching contis on the rear? They're also well regarded, though some suggest they wear pretty fast compared with others.

Well I'm getting a good deal on the Goodyears @ £135 incl fitting. I'm not sure I can get the contis on the rear.
And it seems that a lot of ppl on the forum recommend the Goodyears. The pss are recommended if you have the money I guess