Ask three mechanics about break-in and you will get three rituals. The truth sits between the folklore and the “just drive it” crowd: machining has improved enormously, but piston rings still need their first thousand kilometers to seat properly against the cylinder walls.
What actually happens
A fresh engine’s rings ride on microscopic peaks left by the factory honing process. Under varied load, those peaks wear into a matched surface that seals combustion pressure and controls oil consumption for the rest of the engine’s life. Seat the rings well and the engine burns almost no oil at 200,000 km. Glaze the cylinders instead — usually by holding one gentle constant speed for hours — and it will burn oil forever.
The short version of the rules
Vary the load. Accelerate with moderate throttle, let the engine brake on deceleration, and avoid both lugging and sustained high RPM for the first 1,500 km. Skip the cruise control on day one. None of this requires babying the car; it requires variety.
The oil change question
Many manufacturers no longer specify an early first oil change, but an analysis of used break-in oil almost always shows elevated metal content. A change at 1,500–2,000 km costs little and removes the wear particles of the seating process. We consider it cheap insurance, and it is the one piece of old-school advice we still hand every new-car owner.
