e46 sport. Going from 18's to 17's

[Dino D]

I have 330i sport with the standard MV 18's. 225 front and 225 rear.
It currently has Pirrelli Pzero on the front and Dunlop SP9000's on the rear. The tyres will need replacing in couple months and I want to for a complete matching set and at the same time possilly fit 225 17's all round.

My reasons for considering the smaller diameter wheels and equal width tyres:
I find the car has way too much grip in the dry and tail out fun requires a bit of brutality to unstick the rears.
The car tramlines like crazy.
Bigger wheels dull steering feedback?
Does this car really need wider tyres at the rear? or this is just to encourage safer understeer (currently the same size as an M3 but it has 100bhp less!)
Ride could be better but I doubt the change in tyre size will do much as it mainly due to suspension?
Don't wider tyre aqaplane more?

Anyone done this, have any thoughts? I've driven and e46 sport with 17's but I am hoping to improve the tramlining, have a more'unruly' back end (don't take this the wrong way), improve ride and generally have better riding, steering car.

Any thoughts appreciated.

[anonymous-user]

BMW definately over-tyre the back of M sport cars!

I'm in the process of getting another front wheel & tyre package for the rear, so i can have the same sized tyres all round for my 330d sport tourer. Also i am installing the internals of an M-diff into my diesel final drive / subframe, so that with the inclusion of an M3 rear arb (21.5mm vs 19mm dia) the car should handle a lot better, with the possibility for some nice controllable oversteer with the DSC off.

[Dino D]

max_torque said:

BMW definately over-tyre the back of M sport cars!

I'm in the process of getting another front wheel & tyre package for the rear, so i can have the same sized tyres all round for my 330d sport tourer. Also i am installing the internals of an M-diff into my diesel final drive / subframe, so that with the inclusion of an M3 rear arb (21.5mm vs 19mm dia) the car should handle a lot better, with the possibility for some nice controllable oversteer with the DSC off.

This sounds like an interesting project. Why the hell don't BMW fit lsd's to their 3.0l cars in the first place!!! Not all of can afford to run an M3 everyday!

I think I chatted to you before about the lsd's-I contacted Quaife who make quality diffs for racing but as they have never made on for an e46 they require the original diff and an order for ten usints to go ahead and make the first one...

Let me know how you get on with the narrower rears. You should get some awesome slides with skinnier tyres and an lsd....

[slippydiff]

Dino D said:

max_torque said:

BMW definately over-tyre the back of M sport cars!

I'm in the process of getting another front wheel & tyre package for the rear, so i can have the same sized tyres all round for my 330d sport tourer. Also i am installing the internals of an M-diff into my diesel final drive / subframe, so that with the inclusion of an M3 rear arb (21.5mm vs 19mm dia) the car should handle a lot better, with the possibility for some nice controllable oversteer with the DSC off.

This sounds like an interesting project. Why the hell don't BMW fit lsd's to their 3.0l cars in the first place!!! Not all of can afford to run an M3 everyday!

I think I chatted to you before about the lsd's-I contacted Quaife who make quality diffs for racing but as they have never made on for an e46 they require the original diff and an order for ten usints to go ahead and make the first one...

Let me know how you get on with the narrower rears. You should get some awesome slides with skinnier tyres and an lsd....

I had the 18" MVs swapped for 17" wheels /tyres on my 2002 330D Sport, steerings much less "fidgety" and tramlines much less. The ride i s a lot better (but this will obviously depend on what 17" tyres you decide to fit.

The balance feels much better with 225/45 s all around.

My cars now done 85K miles so I considered buying a newer car a couple of weeks ago.
I test drove 2004 car with 25K and 18" wheels on it, whilst it was a bit more responsive (due to the later 204 hp engine) my car felt a lot nicer to drive. (more planted, steering a bit heavier and more feelsome and it rode the poor road surfaces waaaaay better)
I'm convinced the 18" wheels were a marketing /style led option rather than a "improve the drive option "

[Dino D]

Hey Slippydiff,

What tyres did you run on yours?
I don't like the Dunlop 9000's as the 'squeal' when cornering hard. The PZeros and Goodyear F1's don't squeal but they are not so good for mileage??

Cheers.

[slippydiff]

Michelin Pilot Sports, they're half decent at everything IMO.