New wheels

[hifilover1979]

@garyi , I'm a bit late to the party here but have extensive knowledge of your issues. Firstly ignore the runflat comments, if you're happy with them then move on as they're really not the big issue some people make them out to be. Secondly Merc and BMW have a history with easy to damage OEM alloys that other manufacturers such as Porsche just don't have. Make of that what you will. In your situation I would be looking to either:

source two replacements second hand. What I do when I buy like this is always buy from a company and have them take proper images of both sides of the wheel and ask them to run the wheel on a balancer and check for any buckling. Get them to email this info and tell them if they prove to be unusable you will want a full refund. the reputable ones will have no issue doing this.

OR

find 4 aftermarket wheels second-hand preferably, but be careful. Stick to decent well know brands such as BBS, Ronal and the likes as cheaper wheels could be as bad if not worse than your OEMs. The recognised brands will be forged alloys and much stronger. If you don't recognise a brand do a bit of Googling and the car forums will reveal all. BBS and the likes are expensive new (although not as much as the OEM) hence why I suggest second-hand. What you need to check here is that the wheel size and width but also the offset... this is crucial. The offset is the distance from a wheel's hub mounting surface to the centreline of the wheel. See this diagram:

You will need the offset of your current wheels which are stamped on the back or can be gleaned from the specific model on this database:

BMW OEM Wheels

If you get a set of wheels where the offset is massively different you will get handling issues and possible rubbing of the wheels on the arches.

As an illustration of what I am saying I had a lovely SL55 AMG and put the expensive split rim OEM AMG alloys on it (£3K for a set - secondhand). Bent two irreparably in 12 months. Replaced with BBS forged CH-Rs - were still on when I sold the car 7 years later and in perfect condition.

Feel free to PM me if you want any further specific help.

Some of my favourite wheels; they nigh on suit every car

And FYI most BMW wheels are already made by Ronal or BBS; but not all are forged

 

[stevec67]

Find an independent specialist & ask their advice, they will have contacts who will be able to help.

This approach makes a lot of sense, tap into their expertise so that you don't have to research tyre and wheel technology if it's not your thing, and you'll find a good solution at modest cost, almost certainly a lot cheaper than getting rogered at BMW and having the same problem in 2 years' time.

 

[tiggers]

Some of my favourite wheels; they nigh on suit every car

Couldn't agree more.

And FYI most BMW wheels are already made by Ronal or BBS; but not all are forged

Yes, but I do think there is a different process on many of the OEM ones as they are definitely not as strong as the aftermarket offerings, I think it's not just the forging either, but it's just my gut feeling. Merc OEMs are particularly bad.

 

[hifilover1979]

Couldn't agree more.



Yes, but I do think there is a different process on many of the OEM ones as they are definitely not as strong as the aftermarket offerings, I think it's not just the forging either, but it's just my gut feeling. Merc OEMs are particularly bad.

IMO it's more to do with the fitting of RFTs...

The alloys with normal tyres rarely fail; but now that RFTs are a mainstay; you hear a lot more re cracked alloys etc...

I think the happy medium of this is that if you really want (read paranoid) about punctures and want protection, go for the tyres that have the 'seal' fitted rather than RFTs; for example:

Conti SportContact5 'contiseal': https://www.camskill.co.uk/m61b0s20...Eff_:_C_Wet_Grip:_A_NoiseClass:_B_Noise:_71dB

 

[dweezil]

Couldn't agree more.



Yes, but I do think there is a different process on many of the OEM ones as they are definitely not as strong as the aftermarket offerings, I think it's not just the forging either, but it's just my gut feeling. Merc OEMs are particularly bad.

There are compromises in rim design, light weight is good for handling. Some choose to put any spare weight into the brakes rather than the wheels.

I've got wide rims that are incredibly light and the front discs feel like something off a lorry; then they add Al or Ti wheel nuts.

Would you rather have the occasional cracked rim or a brake failure doing an emergency stop from 155?

German engineers would be appalled at what drivers in Essex call roads.

 

[tiggers]

IMO it's more to do with the fitting of RFTs...

The alloys with normal tyres rarely fail; but now that RFTs are a mainstay; you hear a lot more re cracked alloys etc...

I think the happy medium of this is that if you really want (read paranoid) about punctures and want protection, go for the tyres that have the 'seal' fitted rather than RFTs; for example:

Conti SportContact5 'contiseal': https://www.camskill.co.uk/m61b0s2057p163700/Continental_Tyres_Car_Continental_ContiSportContact_5_ContiSeal_Continental_Conti_Sport_Contact_5_Conti_Seal_-_235_45_R18_94W_SL_FR_TL_Fuel_Eff_:_C_Wet_Grip:_A_NoiseClass:_B_Noise:_71dB

Possibly runflats (stiffer sidewalls) haven't helped, but this was happening a fair time before the prevalence of runflats. I remember all sorts of issues with OEM Merc alloys in the late 90s on the 190 Cosworths and high end AMGs of the time. Anyway I think the OP has some good knowledge now to make a decision. @stevec67 's idea is a good call tbh as it doesn't sound like the OP wants to get into the whole petrolhead world of aftermarket alloys

 

[Tony Lockhart]

Possibly runflats (stiffer sidewalls) haven't helped, but this was happening a fair time before the prevalence of runflats. I remember all sorts of issues with OEM Merc alloys in the late 90s on the 190 Cosworths and high end AMGs of the time. Anyway I think the OP has some good knowledge now to make a decision. @stevec67 's idea is a good call tbh as it doesn't sound like the OP wants to get into the whole petrolhead world of aftermarket alloys

The Merc 190 went out of production in 1993

 

[tiggers]

There are compromises in rim design, light weight is good for handling. Some choose to put any spare weight into the brakes rather than the wheels.

I've got wide rims that are incredibly light and the front discs feel like something off a lorry; then they add Al or Ti wheel nuts.

Would you rather have the occasional cracked rim or a brake failure doing an emergency stop from 155?

German engineers would be appalled at what drivers in Essex call roads.

No I'd rather have lightweight strong alloy wheels that don't crack and no brake failures. This is why I fitted CH-Rs to my AMG. CH-Rs are about 12kg, AMG IVs are about 22kg. The AMG brakes are heavy but good quality. Never any issues even running the car round Spa on an AMG weekend away. Sorry, but there's no excuse from the likes of BMW or Merc for their shoddy alloys.

 

[tiggers]

The Merc 190 went out of production in 1993

Yep and they were huge in the AMG/Merc scene around the end of the 90s when they became more affordable so not sure of the relevance of your post.

 

[Tony Lockhart]

Yep and they were huge in the AMG/Merc scene around the end of the 90s when they became more affordable so not sure of the relevance of your post.

Well I suppose if the wheels had issues at 6+ years old, there’d be less concern from the manufacturer. Buying used performance cars is fraught with risk, from the ground up.

As my local Merc specialist told me, every car has its Achilles heel, but some will have more.

 

[stevec67]

Possibly runflats (stiffer sidewalls) haven't helped, but this was happening a fair time before the prevalence of runflats. I remember all sorts of issues with OEM Merc alloys in the late 90s on the 190 Cosworths and high end AMGs of the time. Anyway I think the OP has some good knowledge now to make a decision. @stevec67 's idea is a good call tbh as it doesn't sound like the OP wants to get into the whole petrolhead world of aftermarket alloys

I don't think it was my idea, someone else first suggested it. I just think it makes sense. As for whys and wherefores, the snag is that the advent of RFTs etc has gone hand in hand with lower profile tyres, bigger and heavier wheels, bigger and heavier cars, and so on. Who knows what the primary cause is? I had a cracked rim on a Mondeo, I think it was on 55 or even 60 profile, but that was just my crap driving and clouting a kerb on the A38 around Derby. 2 years and 30k miles in a 35-shod Audi has had no such drama other than one slightly wobbly rim that the previous owner managed, honest guv. As a student I even kinked a steel rim on a Fiesta running 145 x 12" tyres, but in those days the tyre shops would remove the tyre, heat the rim with oxy-acet and pull it back with a pair of Stilsons and or the big hammer.

 

[tiggers]

As a student I even kinked a steel rim on a Fiesta running 145 x 12" tyres, but in those days the tyre shops would remove the tyre, heat the rim with oxy-acet and pull it back with a pair of Stilsons and or the big hammer.

I did exactly that when I was a student and on a Fiesta too

 

[tiggers]

Well I suppose if the wheels had issues at 6+ years old, there’d be less concern from the manufacturer. Buying used performance cars is fraught with risk, from the ground up.

As my local Merc specialist told me, every car has its Achilles heel, but some will have more.

Mercs being the worst offenders in my experience. Not just wheels btw. Thank goodness I have seen the light and got back in to my Japanese cars.

 

[garyi]

Okey here are my wheels

Pretty certain they are just the bottom of the pile option along with the rest of this car, the stereo is truely awful!

 

[garyi]

@garyi , I'm a bit late to the party here but have extensive knowledge of your issues. Firstly ignore the runflat comments, if you're happy with them then move on as they're really not the big issue some people make them out to be. Secondly Merc and BMW have a history with easy to damage OEM alloys that other manufacturers such as Porsche just don't have. Make of that what you will. In your situation I would be looking to either:

source two replacements second hand. What I do when I buy like this is always buy from a company and have them take proper images of both sides of the wheel and ask them to run the wheel on a balancer and check for any buckling. Get them to email this info and tell them if they prove to be unusable you will want a full refund. the reputable ones will have no issue doing this.

OR

find 4 aftermarket wheels second-hand preferably, but be careful. Stick to decent well know brands such as BBS, Ronal and the likes as cheaper wheels could be as bad if not worse than your OEMs. The recognised brands will be forged alloys and much stronger. If you don't recognise a brand do a bit of Googling and the car forums will reveal all. BBS and the likes are expensive new (although not as much as the OEM) hence why I suggest second-hand. What you need to check here is that the wheel size and width but also the offset... this is crucial. The offset is the distance from a wheel's hub mounting surface to the centreline of the wheel. See this diagram:

You will need the offset of your current wheels which are stamped on the back or can be gleaned from the specific model on this database:

BMW OEM Wheels

If you get a set of wheels where the offset is massively different you will get handling issues and possible rubbing of the wheels on the arches.

As an illustration of what I am saying I had a lovely SL55 AMG and put the expensive split rim OEM AMG alloys on it (£3K for a set - secondhand). Bent two irreparably in 12 months. Replaced with BBS forged CH-Rs - were still on when I sold the car 7 years later and in perfect condition.

Feel free to PM me if you want any further specific help.

Brill thank you, I am guessing from mine that its positive offset. will check out your link. I think my car is an F30. IDK, they seem to make it purposefully complicated.

 

[stevec67]

Somewhere on the rim, usually inside, there is a size. Say 8J x 18 and another digit describing offset. Quote this.
It's not complicate d, it's only like reading a tyre spec.

 

[hifilover1979]

Okey here are my wheels

Pretty certain they are just the bottom of the pile option along with the rest of this car, the stereo is truely awful!

So they're Style 398s:

https://www.auto-treff.com/wcf/index.php?article/397-styling-398/

And; there's a set with Quarry Motors:

https://www.ebay.co.uk/itm/28457989...d=link&campid=5338728743&toolid=20001&mkevt=1

 

[tiggers]

Somewhere on the rim, usually inside, there is a size. Say 8J x 18 and another digit describing offset. Quote this.

Prefaced by ET usually. ET is the short form of the German word 'Einpresstiefe' which literally translates as 'insertion depth' - thank you Google!

 

[tiggers]

Brill thank you, I am guessing from mine that its positive offset. will check out your link. I think my car is an F30. IDK, they seem to make it purposefully complicated.

No worries, feel free to give me a PM if you want any direct help. @hifilover1979 knows his stuff too though so between us I am sure we can provide the knowledge you need.

 

[hifilover1979]

Prefaced by ET usually. ET is the short form of the German word 'Einpresstiefe' which literally translates as 'insertion depth' - thank you Google!

it'll be on one of the rears of the spokes; but the link I've provided gives all the wheel specs inc offset and weights etc as well as the correct OEM tyre sizes