Originally Posted by drsnooz
There must be a good reason for BMW to recommend a soft break-in for a new vehicle otherwise they wouldn't mention it in the owner's manual. Don't know about you but I'm not going to destroy a $70K (potentially) vehicle right out of the box. I'm going with the soft break in.
There are several good "mechanical" reasons not to drive it hard out of the lot as the moving parts in the drivetrain need to wear out together. The first few thousand miles is when the friction in those components is the highest, and it doesn't make sense to me to push a system that is stressed more than its optimal operating conditions harder than its recommended limits. Not only could you literally bust something (you'd really have to try though), but you could also end up with higher than intended tolerances in the drivetrain, which would be there for the life of the car.