[MOB]

Hi All

I've recently bought an 07 325d M Sport - black with Lemon leather.

Love the car, but I'm having real issues with the car tramlining on uneven or rutted surfaces - the car has Bridgestone RE50 (I think thats the code) RFT's

The ride quality is fine though.

I'm considering changing all 4 tyres to Goodyear F1's or Michelin PS Sports (both non-RFT's)

Has anyone else changed their tyres for this reason?

Cheers

[E92Fan]

Absolutely - I changed over to PZero Neros (although I wanted Michelin's but unavailable at the time). The ride is much better - secondary ride is particular - but more impressive is the fact that the car tramlines less. However, you will always get tramlining on our cars because of the size of tyres and the geometry of the suspension. The trick is to try and minimise this without losing the front-end bite and precision of the steering.

If you are happy with the ride quality on the Bridgestones, then I'd actually suggest you check the tyre pressures on your car first to see if that helps with the tramlining. Are you on 19" wheels or 18" ? Try a front pressure of 2.7-2.8 bar, with the rears at 3.0bar (manual says 3.2bar on the back, but you'll find greater stability by reducing the back a little)

[E92Fan]

Oh, and welcome to the forum! Hope it's not the only post you will make

[dxb335d]

Welcome to the Forum matey!!

Im am Ze Carloti (Carlos really) Get A KDS, alignment check if its that bad.

[MOB]

Cheers for the reply - I'm on 18" wheels

I will check the tyre pressures though - I had a look at the label and I think that said something like 46psi in the rears - that cant be right??

What sort of pressures should they be do you think?

[E92Fan]

Originally Posted by MOB

Cheers for the reply - I'm on 18" wheels

I will check the tyre pressures though - I had a look at the label and I think that said something like 46psi in the rears - that cant be right??

What sort of pressures should they be do you think?

Read my post above!!! I already told u the tyre pressures...! (if you can't read bar pressures, then try 40psi front, 43.5psi back)

[MOB]

Also meant to mention that my missus currently has a Cayman S, and is seriously considering changing it for a 335i M Sport Coupe after driving mine.

Not that the Cayman is a bad car (its sublime) but a 335i we test drove felt at least as fast, much more comfy and less likely to be car-jacked lol!!

[MOB]

Originally Posted by E92Fan

Read my post above!!! I already told u the tyre pressures...! (if you can't read bar pressures, then try 40psi front, 43.5psi back)

oops my bad

Cheers

[E92Fan]

Originally Posted by dxb335d

Welcome to the Forum matey!!

Im am Ze Carloti (Carlos really) Get A KDS, alignment check if its that bad.

Tramlining is not an alignment/KDS issue unfortunately - it is just a consequence of the car being influenced by road camber and ruts. If however the car is drifting constantly either to the left or right, regardless of camber, then that will be an alignment issue. There are no easy cures to tramlining - a change of tyres might help (though not necessarily) and certainly checking tyre pressures and adjusting accordingly will be of greatest benefit.

[E92Fan]

Originally Posted by MOB

Also meant to mention that my missus currently has a Cayman S, and is seriously considering changing it for a 335i M Sport Coupe after driving mine.

Not that the Cayman is a bad car (its sublime) but a 335i we test drove felt at least as fast, much more comfy and less likely to be car-jacked lol!!

Wow, first person I've heard who wants to jump out of a Cayman S !! I can understand coming out of a standard Cayman, but the S is a great car and drives fantastically. Yes, the 335 is more comfortable over long journeys but doesn't involve the driver in the same way. Straight line speed, there's not much in it...

[red-max]

E92Fan, what tyre pressures are you running your PZeros at? The BMW recommended pressures do seem extremely high, and I'm wondering if they're only valid for RFTs. For those of us switching to non-RFTs, is there a scientific way to determine what pressures we should be running (rather than trial and error)? I couldn't find anything useful on the Michelin website, but I suppose it depends not only on the tyre size but also the weight of the car. Anyone know what tyre pressures Alpina recommend for their cars?

[E92Fan]

The BMW tyre pressures are only really valid for the RFTs - because of their stiffer sidewall structure, you need to run higher pressures to prevent excessive feathering of the tyre shoulders. It's a real irritant!

On the non-runflats, I use the Alpina settings which are 2.6bar front, 2.7bar rear (or 37.7psi front, 39.1psi rear) - these settings are great because it gives the car great front-end bite, good handling, and good comfort too (bear in mind that these are for 19" wheels)

[E92Fan]

One other thing though - you have a 335d which has a heavier engine that the 335i petrol and you use 18" wheels. Therefore, you should go with 2.75bar (39.8psi) at the front and 2.8bar at the back. Don't go any higher at the back unless you have a full load or always carry two large passengers - in which case use 3.0bar at the back. Under normal driving circumstances though, revert to 2.8bar

ps.. all above derived from Alpina's experience

[red-max]

Originally Posted by E92Fan

One other thing though - you have a 335d which has a heavier engine that the 335i petrol and you use 18" wheels. Therefore, you should go with 2.75bar (39.8psi) at the front and 2.8bar at the back. Don't go any higher at the back unless you have a full load or always carry two large passengers - in which case use 3.0bar at the back. Under normal driving circumstances though, revert to 2.8bar

ps.. all above derived from Alpina's experience

Thanks very much, I will give 40 front, 41 rear a try. I think I'm running 36 or 37 at the front now, and they seem a little soft.

[E92Fan]

Originally Posted by red-max

Thanks very much, I will give 40 front, 41 rear a try. I think I'm running 36 or 37 at the front now, and they seem a little soft.

Yes, 36/37 is too soft and will give you quite a bit of plough-on understeer and inprecision in steering. You might also be getting exaggerated tramlining. Let us know how you get on with the new pressures.

[Budgie]

Hey MOB welcome ...I jumped ship from TABS and the gang recently too..the 325d is what a replacement for your Volvo i guess?.

Anyway have fun and knowing you ....ull have a 335d soon anyway.

Cheers B

[creepy coupe]

Originally Posted by E92Fan

Try a front pressure of 2.7-2.8 bar, with the rears at 3.0bar (manual says 3.2bar on the back, )

Are you sure, my door card says 2.1 (30.4 psi) with up to 3 persons, I'm on 18's bridgstones and have no tramline issues.

PS Hello Mob

[NFS]

Originally Posted by E92Fan

Yes, 36/37 is too soft and will give you quite a bit of plough-on understeer and inprecision in steering. You might also be getting exaggerated tramlining. Let us know how you get on with the new pressures.

I agree - your pressures are too low, which will affect the handling and reduce the life of the tyres.

I have the same tyres (Bridgestone RE50 runflats) on 18 inch wheels.

Recommended pressures are shown inside the drivers door. I go midway between the full and part load for both front and rear.

I got 25,000 miles out of my last set of tyres and the front ones could probably have managed 5,000 more.

[Budgie]

Yeah true mine dont say that but do remember we got 320d coupes creepy and he has a 325d saloon?.I personally dont have trouble unless i go in the inside lane of the motorways and the juggernauts have worn a tramline themselves but then its self explainatory isnt it,

[mjh93sa]

I haven't found this sort of problem on my MSport, but if you plough through my post regarding the SE that I was driving recently you'll see that this was a complete pig for tramlining.

Tyre pressures on both set exactly as per the door card plus 0.5bar, the SE on 17" and the MSport on 18".

... and welcome!

[MOB]

Originally Posted by Budgie

Hey MOB welcome ...I jumped ship from TABS and the gang recently too..the 325d is what a replacement for your Volvo i guess?.

Anyway have fun and knowing you ....ull have a 335d soon anyway.

Cheers B

lol - I actually drove a 335i, 335d, 330d and 325d and went for the 325d - the others were quicker but not dramatically so IMO (335i aside)

It has replaced my S40 D5 - that had 180bhp and the 325d has 197bhp.

But there is no way on this earth that the difference between the 2 cars is only 17bhp - feels more like 50bhp at least

[NFS]

Originally Posted by MOB

But there is no way on this earth that the difference between the 2 cars is only 17bhp - feels more like 50bhp at least

Ahh ... but the D5 has 350Nm of torque and the 325d has 400Nm