Tyre profile size

[BaJ]

Howdy all,

My Z4MC is at BMW today having the brake fluid changed as it's due. I've just had a call from them to say it's all ready but the technician noticed the front tyres were the wrong profile for the car.

I'll be totally honest and admit to not ever noticing, I'm not even sure how different they are to standard as I've not got the car back yet. However ... I purchased the car from the same BMW dealership 11 months ago and it came with these tyres fitted. Should they not of sold it with the correct profile tyres in the first place?

Do I have a leg to stand on if I kick up a fuss do you think? I can't say it massively bothers me and I've never noticed it, but if I can get a fresh set out of them then all the better

 

[playalistic]

Hell yeah. I'd have a go and see what gives. Nothing to lose really is there!

 

[peddy]

What is the profile? should be 45 on the front and 40 on the rear.

 

[dgm]

From the photos on your for sale thread, you have 225/40/18 on your fronts. Should be 225/45/18 as above. Worth a go at asking for replacements although you'll probably get the technician shot. :lol:

 

[peddy]

I think they should definitely replace them... Especially if it was a BMW approved one.

 

[mmm-five]

Can you prove that the tyres on there are the same as the ones that were on the car 11 months ago. For example, can you show them that you've only done 1,000 miles since you bought it and they were 6mm or so when you bought them, so you'd have been unlikely to swap them for the wrong ones in that period.

Are they Continental SportContact M3 tyres? I didn't think they came in anything other than 225/45 and 255/40 sizes.

 

[Darren M]

A mistake made is the belief that all 18" Z4 tyres sizes are the same profile. A large tyre place queried me a year ago when I told them the size tyres I needed "oh sir but that's the wrong size for the COupe".....'no not the M ya numpty came the reply :evil: The 40 profile was fitted to the Si's fronts but not the M.

unless the dealer replace them for free, just run with them until worn downout is what I'd do

 

[mmm-five]

A mistake made is the belief that all 18" Z4 tyres sizes are the same profile. A large tyre place queried me a year ago when I told them the size tyres I needed "oh sir but that's the wrong size for the COupe".....'no not the M ya numpty came the reply :evil: The 40 profile was fitted to the Si's fronts but not the M.

If they've fitted non-M tyres by mistake then you'd think they'd be runflats which the dealer should have noticed. If they fitted M size tyres then they can't be the 'official' tyre as they don't come in 225/40/18.
Although I'd still think it's a bit of caveat emptor and the best you can hope for from the dealer is a bit of goodwill contribution towards a new pair - assuming the ones on there are not almost bald and need replacing anyway.

 

[peddy]

Also, remember with a wrong profile your speedo will be off by around 3.5% more than it should be, so when it shows 70mph you'll be doing around 67mph. I'm guessing it effects your milage aswell then right? If so, it will not be much.

 

[Dogmatic6]

I'm running the wrong profile all round in my M. I ordered the wrong size Vreds by mistake (3.0si runflat sizes) and just decided to live with it. As has been said the speedo is out by around 3.5% and the ride is a little more firm but the vreds have amazxing grip in the wet. Just more of an excuse to try and wear down the tyres as quick as possible

Another more serious effect for me is that traction control deavtivates itself on certian journey's. It must be something to do with the wrong profile size messing up the calculations. Only started when I got the new tyres fitted and only happens on long straight road journey's doesn't happen on twisty roads...lol

 

[Darren M]

Another more serious effect for me is that traction control deavtivates itself on certian journey's. It must be something to do with the wrong profile size messing up the calculations. Only started when I got the new tyres fitted and only happens on long straight road journey's doesn't happen on twisty roads...lol

THat's intersting. How do you know it#s deactivated, does the light come on the dash?
I'm using 225*40`s all round (winter tyres) and don't have that problem. I do notice the TC seems to start kicking in earlier though even on cold mornings, a condition where the tyres should produce more grip so have put this down to the smaller circumference tyres. THis happens when accelerating over like a bump in the road (poor road repair).Used to get this with the Conti M3's on the same road but under harder acceleration.

 

[Dogmatic6]

Another more serious effect for me is that traction control deavtivates itself on certian journey's. It must be something to do with the wrong profile size messing up the calculations. Only started when I got the new tyres fitted and only happens on long straight road journey's doesn't happen on twisty roads...lol

THat's intersting. How do you know it#s deactivated, does the light come on the dash?
I'm using 225*40`s all round (winter tyres) and don't have that problem. I do notice the TC seems to start kicking in earlier though even on cold mornings, a condition where the tyres should produce more grip so have put this down to the smaller circumference tyres. THis happens when accelerating over like a bump in the road (poor road repair).Used to get this with the Conti M3's on the same road but under harder acceleration.

Well I get an audible beep then the TC lights up on the dash along with a yellow handbrake light. It then wont go back to normal until I stop/start the engine.

I'm running 225/40 at the front and 255/35 at the rear and I'm guessing this is whats causing the problem. It doesnt happen on every road.

I made the mistake as I typed in my reg number to a web site and it told me the wrong sizes

 

[chris]

If they are conti's and ok, then if you fancy a swap with some decent conti contact sport 2 M3 tyres then have mine