Hi, first post and wanted some advice please. Purchased my approved used Z4 2.0i in January and had two new rear tyres fitted by BMW the other day, just taken the wheels off to wax them after reading someones advice on here and noticed that the two rear alloys are different. They both have 225*35*R18 90W tyres however one rim is 8J and the other is 8.5J both fronts are 8J with 225*40*R18 88W tyres. My understanding is that the rear alloys should be 8.5J on both, can someone confirm this and advise if this is likely to be detromental as I am having a nightmare already with the BMW delear.
z4 staggered alloy set up
- Thread starter weby23
- Start date
Do you mean the rears are 255/35/18? Or really 225/35/18?
If the later that is so wrong on so many levels, esp fitting it to the correctly spec'd 8.5j.
Sounds like they replaced a bucked rear with a front... So now the rears dont match. Idiots!!
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If the later that is so wrong on so many levels, esp fitting it to the correctly spec'd 8.5j.
Sounds like they replaced a bucked rear with a front... So now the rears dont match. Idiots!!
Sent from my iPhone using Tapatalk
If you have a staggered set up you should have 8j on the front with 225/40/18s and 8.5j on the rears with 255/35/18s fitted.
Firstly the rear wheels should be the same width because the tyres will perform differently when cornering.
Secondly if you have 225/35/18s on the rears your the rolling radius will be incorrect and lead to an inaccurate speedometer reading.
As previously said it is likely a front wheel has been put on the rear for some reason and you need to get it sorted.
Firstly the rear wheels should be the same width because the tyres will perform differently when cornering.
Secondly if you have 225/35/18s on the rears your the rolling radius will be incorrect and lead to an inaccurate speedometer reading.
As previously said it is likely a front wheel has been put on the rear for some reason and you need to get it sorted.
Dav the wheel nut said:
Will the diference really affect the speedometer reading? I work it out that the difference between 225/40 and 255/35 is 1.5 mm.
I increased my rear tyre/wheel diameter by approx 15mm when I upgraded to 19" wheels and can't say I've noticed the speedo shows any noticeable diference (using sat nav for comparison).
hype said:
That's correct, but I didn't see anything in the original post that suggested there was a 255 width tyre fitted on the car.
Not that it really matters, but I got 1.75mm calculated difference, a 0.24% circumference change. In reality, it'll be less because the 225 will be stretched on to an 8.5in wheel, reducing it's calculated height a bit.
The only real problem is an unmatched setup on the same axle.
The only real problem is an unmatched setup on the same axle.
There is absolutely no problem with putting 225's on a 8.5 rim, the tyre however will offer no sidewall protection and it looks unsightly IMO.
However having two different width wheels on the same axle, is not a great idea due to the difference in mass, take it back to the dealer
However having two different width wheels on the same axle, is not a great idea due to the difference in mass, take it back to the dealer
Thanks everyone for your replies regarding my staggered alloy set up and the issue with the two rear alloys being 8J and 8.5J after being told by the service manager that he didnt know what I was talking about thanks to the forum I did and he has 'learnt something new'. He has accepted that they 'missed' the error during the 'intensive' pre sales checks,.
Does anyone know if having these two differing widths would have affected tyre depth or anything more severe (they say there is no danger or issue at all) becuase after 5 months of owning and 4,000 miles I have had to have both rear tyres replaced as they were 1.8mm and 2.3mm. Not sure with it being rear wheel drive how long they should last but I am not happy that I have had to have these replaced after buying the car from a main dealer 5 months ago.
They are offering to replace one of the alloys but I am pushing now for a new set due to the lies they spun me when I bought it. I would also very much like to get my £520 back for the tyres.
Any advice would be great.
Thanks
Does anyone know if having these two differing widths would have affected tyre depth or anything more severe (they say there is no danger or issue at all) becuase after 5 months of owning and 4,000 miles I have had to have both rear tyres replaced as they were 1.8mm and 2.3mm. Not sure with it being rear wheel drive how long they should last but I am not happy that I have had to have these replaced after buying the car from a main dealer 5 months ago.
They are offering to replace one of the alloys but I am pushing now for a new set due to the lies they spun me when I bought it. I would also very much like to get my £520 back for the tyres.
Any advice would be great.
Thanks
I think the official line from BMW is that they'll replace tyres with less than 3mm thread left for AUCs - if yours were down to this when you purchased then 4,000 miles could easily have taken another 1.5mm off.
If I was you I'd overplay the inconvenience having to take the car back to them has caused you and get whatever you can. Good luck!
If I was you I'd overplay the inconvenience having to take the car back to them has caused you and get whatever you can. Good luck!
sars said:
I'm already spaced out man.
15mm hubcentrics each side as the 108s sit way too far in the arches as standard. Some go 20mm at the rear with 108s. Whatever the track the tyre width just looks a little narrow to me for 3 litres and 230bhp.
I also agree that the 255s look almost stretched over the rim and provide no protection to even the slightest of kerbing.
Think I'll go for 265s on the back and 235s (if they exist) for the front next tyre change though I only do around 4k miles a year and my tyres are new at the moment so this will not be for a good while yet!
The 265s look right and the 255s look wrong as if they are too small for the rim and are a bit stretched.
Wish I'd realised this before I bought the apparently right size tyres for all four corners just a few weeks ago!!!
Looks like the step up in size looks better (more correct in fact) and provides a lot more protection to those annoying kerb grazes.
Wish I'd realised this before I bought the apparently right size tyres for all four corners just a few weeks ago!!!
Looks like the step up in size looks better (more correct in fact) and provides a lot more protection to those annoying kerb grazes.
Weirdly, 255s on my rear 108s look nothing like that - they fill out the sides nicely and have rim protection. They are Michelin PS3s. Agree about the standard track - the wheels sit too far in and don't look right - but I think spacers help massively without changing the rubber. I have 20s on the rear right now and 15s on the front. Think I am going to swap the 15s to the back and get some 10s or 12s for the front.
If you really want better stance and wider tyres then get some ///M wheels. They sit right out on a non ///M Z, and the rears are 265 on a 9J rim IIRC. They look awsome
If you really want better stance and wider tyres then get some ///M wheels. They sit right out on a non ///M Z, and the rears are 265 on a 9J rim IIRC. They look awsome