Which OEM wheels are prone to cracking?
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From: Virginia USA
2016 GTs, 2014 C63 AMG and 2014 C350 Sport (wife's car, she thinks it's an AMG - shhhhhh)
Which OEM wheels are prone to cracking?
Saw a few mentions of some AMG wheels prone to cracking. But I can’t recall which thread it was in. Since it’s a known issue (I think) can someone post a pic of the problematic style please?
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
....or not running high enough tire pressure especially in 19" wheels. The 19" AMG V 16 multispokes are probably the worst for cracking. BLK beat me to it. 
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W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
All of them are prone to cracking when the rim hits the pavement. It's just easier to to do with a wheel with an underinflated 255/30-19 tire than on one that has a higher sidewall and/or more air in it.
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From: Australia
2011 C63 AMG P31
If under inflated, all rims will crack. However, the 19" do obviously require a bit more maintenance given there is less room for error. It is unlikely a rim will just "crack" on its own & if that was the case, there would be a huge recall, as that is a safety concern. A cracked rim is the outcome, but what you will need to find is the cause... was it the road? Driver? Air Pressure? etc - is it a non rated after-market rim?
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W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
If under inflated, all rims will crack. However, the 19" do obviously require a bit more maintenance given there is less room for error. It is unlikely a rim will just "crack" on its own & if that was the case, there would be a huge recall, as that is a safety concern. A cracked rim is the outcome, but what you will need to find is the cause... was it the road? Driver? Air Pressure? etc - is it a non rated after-market rim?
The cause of rims cracking in street applications is almost always the rim hitting a hard object, usually in the form of a pothole on the pavement. Whether the rim is stock or aftermarket, at what speed the vehicle hit the pothole, how inflated the tires were and how sharp the pothole edges were and their precise geometry relative to the rim lips all play in role, but they were all a result of a hit. Nothing else. Are some rims stronger than others? Absolutely... but that simply means that stronger rims are able to absorb an impact of a certain force without (obvious) damage whereas weaker rims cannot and they crack or bend.
In racing applications rims can also crack due to fatigue, but the lateral forces that they are constantly exposed to in that environment are simply not achievable on public roads and/or with street tires.
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2010 Irridium Silver MB C63 AMG Sedan
I keep my OEM multispokes at 36-40 psi. Not one problem now for 6 years. There are many vids out there as to how well OEM wheels are made. All wheels can crack, it depends on external factors and end user.
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From: Australia
2011 C63 AMG P31
I'll clarify and say with a bigger rim (smaller sidewall on a tire) you need to stay on top of your tires air pressure more-so then if you had a taller sidewall
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^ That is correct. The shorter the sidewall, the higher the required air pressure in the tire to prevent the rim from compressing the tire completely and the rim lip hitting the pavement when it hits a pothole. 
As a VERY GENERAL rule of thumb, on most vehicles I've seen that are offered with different size wheels tires, for every 1" of increase in wheel diameter (assuming that the overall tire diameter / circumference stays the same) the pressure needs to go up by about 4 psi.
As a VERY GENERAL rule of thumb, on most vehicles I've seen that are offered with different size wheels tires, for every 1" of increase in wheel diameter (assuming that the overall tire diameter / circumference stays the same) the pressure needs to go up by about 4 psi.
