[HUM5INT]

'21 M5C LCI - So had my 1200 mile break-in completed successfully. Per the service order there were 4 specific line items completed:

1. Diff fluid replaced front and rear (btw there's a shortage of diff fluid so check to make sure they have it in stock for service)
2. Oil change
3. Other vehicle fluids
4. LC System and engine config check

They also did the typical end to end vehicle inspection- nothing remarkable except inflating tires to 36-37 psi.

Impression…what I expected. My "butt" dyno suggests it's faster on WOT…but it's also the first time I'm actually pushing it WOT since I painstakingly have kept it to sub-4,000 rpm. So there's no baseline comparison.

Response does feel more free-flowing and less tight - again not significantly enough where I can say the service really changed it.

Finally I read posts of the sound being dampened after break-in….definitely NOT the case. This is the one true thing I can say has in fact gotten significantly better post service - deeper, more pops / burbling and it lasts much longer than before even in 3+ gear.

All in all VERY happy with my service, the crew and the dealership.

[phoenixbmwlife]

I can remember doing the 1200 mile service on my M5C like it was yesterday. I kept saying "what the hell" over and over again for like 5 minutes. No joke! It really shocked the hell out of me how much it opened up. It sounded louder and felt faster even though like you, I waited until after 1200 service to do WOT. Truly an awesome machine!

[TimmyBHGM5]

I am at 700 miles, looking forward to the breakin service

[HUM5INT]

Originally Posted by TimmyBHGM5

I am at 700 miles, looking forward to the breakin service

Getting to 1200 feels like the longest enduring process ever but you'll get there!

[Day Laborer]

I'm surprised that they did change the front differential fluids.

Several members here including myself have mentioned that this service isn't included on LCIs anymore.

I had mine replaced under goodwill

I've also noticed different past numbers for the front diff for LCIs too

[HUM5INT]

Originally Posted by Day Laborer

I'm surprised that they did change the front differential fluids.

Several members here including myself have mentioned that this service isn't included on LCIs anymore.

I had mine replaced under goodwill

I've also noticed different past numbers for the front diff for LCIs too

That's interesting because the service associate definitely said everything done is very much a key component of 1200 mile break in per M vehicle requirements. Luckily you still got yours done!