Question on 296 wheels

[craniac24]

Hey everyone. I’ve got a 2011 MT s35i on the way next week. Super excited! I did a fair amount of research before purchasing, but one thing I missed until just now was the fact that the 296 wheels on that car are notorious for cracking. I also understand that BMW made some changes to the design of that wheel in order to prevent cracking in the future.

When my car arrives, I’m going to take it to a local shop for a complete inspection. I plan on asking them to pay special attention to the wheels to see if there any cracks, but just as importantly, I’m hoping someone here can let me know how to tell the difference between the old, defective style wheel, and the new improved version.

Thanks in advance for your help!

[B21]

Welcome..the rear wheels..not sure about the fronts had a much thicker casting around the inside rim..you should be able to Google a pic of the two versions for comparison

[KennyP]

As i understand 296 isnt the only wheel that has cracking issues... 19" 326 can develop cracks aswell... so its more like an issue with 19" rims in general.

i have had 296 wheels for over 7 years now..

at first when i got the car they had oem runflats on them... after a few years i did develop a few cracks on the inner edge of the rear wheels.
had cracks fixed and the whole wheel set refurbished... and got rid of runflats at the same time... switched to michelin supersports.
About a year or max 2 later found another crack again. This time went to a different place and had it fixed and painted. It may have been a bad repair by the first place i went to, that had to be repaired again.

After that its been 3-4 years and no new cracks have developed. I do check them when i happen to get the car on a lift or when i change tires or swap to and from winter wheels.. i guess getting rid of runflats did help.

Developing cracks dont result in catastrophic failure. Air will start slowly to leak out of the crack... so you will start getting "tire pressure low" messages from the tpms on the idrive. this usually happens when tire is still more than half full. So you can drive slowly to the station and fill it up. But message would come back in a few days.

things that help to avoid cracks from developing:
dont use runflat tires
regularly check that your tirepressures are in check... say once a week... and often rears are about 0.2bar lower than they should. TPMS would not notify you of it... tire pressure has to be alot more lower to trigger an error message. if i remember correctly tpms starts giving an error when tire pressure is about 0.4 bar lower.
Also im talking about the TPMS that doesnt have sensors in the wheels and works by measuring the rolling diameter of the wheel.

Also lowering negative camber of the rear wheels when doing alignment would help.

TBH i still dont know if i have the original version of the 296 or the improved version... i think you cant really check it without taking the tire off the wheel, can you?

[B21]

The change is obvious from the outside if you have the two versions to compare..I did see a picture somewhere showing two side by side..

But now I’m starting to think was it the 325M?