2012 370Z Oil Temp

ImportConvert

Because everything stretches in an engine. If you cruise at ONE rpm, you will wear the cylinder walls to ONE depth only on the piston stroke, etc.

City driving is best, you are MAINLY breaking in the driveline, and rowing through the gears placing torque on the gear-faces (and backs of them, as you coast to a stop using the engine), lapping them in.

The reason you don't want to break the engine in at 7K rpm is because you are ALSO breaking in the bearings, and load-bearing surfaces of the engine. Not just rings/pistons. Nissan knows WAY more about their VQ than I do. However, engine harmonics caused by high rpm, extra stress on the crank, etc. could adversely affect the bearings and perhaps the unique VQ valvetrain in a negative way. If it were just cylinders and rings, then maybe your way would be the best way.

THE BEST way to break in a car is running the engine on a dyno under load.
Then you put it in the car and proceed to break in the transmission, rear-end, and brakes.

Unfortunately, this is only done on certain high-end cars. SO we are stuck breaking in the engine and driveline at the same time, both of which prefer slightly different behavior, and the brakes, which to bed, require entirely DIFFERENT behavior.

GM's manual on the ceramic brakes is especially confusing.

They state that rpm should be kept under 3K for 500 miles and no faster than 55mph (this is from memory when I owned my Z06, but yet that the brakes should be broken in soon and that you should do this by accelerating as fast as possible to 60, braking hard to impending lock-up, and wash-rinse repeat.

Not exactly an under 3K and "no hard shifting" and keep it at 55 or less proposition.

Alas, we are stuck with a system, and each owner works out in their own mind what they think is the best compromise.


http://www.aera.org/downloads/BIP.pdf
http://www.stockcarracing.com/techar...n/viewall.html