With the significant improvements in engine construction techniques in recent years, running in a new vehicle is nowadays rarely considered.
But essentially, the principle hasn’t changed: your engine’s mechanical components must first be “run in”, in spite of close production tolerances. The piston rings and cylinder wall of a new engine, for example, will not yet have been completely run in. As such, I recommend that you avoid overly high engine rpms for the first 3,000 kilometres. With a diesel engine, you should stick to around 2,500 rpm for the first 1,000 kilometres, and to around 3,000 rpm for a petrol engine, depending on the vehicle type. Because of the resulting friction, the interacting mechanical parts will adapt increasingly during the run-in phase. I would also advise against long motorway journeys at constant speeds. To ensure the optimal run-in of your new engine, speed fluctuations and different load conditions are ideal. Opt therefore for national roads with topographical variations. As the number of kilometres increases, you can gradually increase the rpms. Thanks to an enhanced filtering technology and high-quality engine oil, an oil change is generally unnecessary at an early stage, unless of course the manufacturer recommends otherwise.
What goes for the engine and transmission also applies for the braking system: the pads must be run in on the brake discs, a process requiring a distance of around 300 kilometres. When decelerating, the braking system temperature increases, while the surfaces of the new discs harden increasingly during the run-in phase. Excessive braking manoeuvres, however, can cause permanent damage to the discs during the run-in, resulting in vibrations through the steering wheel during braking.
And pay attention to your new tyres, they too need to be run in due to the product manufacturing process. To optimise the removal of the tyre from the mould after its fabrication, it is coated in a mould-release agent. Depending on the type of tyre, this slippery coating must be “worn down” over a distance of 150 to 300 km. Only after travelling this distance will you benefit from the tyre’s full traction potential. You should therefore be cautious when braking and turning!
Even the new shock absorbers won’t be fully effective at the start. In practical terms, this means that wheel adherence is not yet perfect and that comfort will leave a lot to be desired. These examples illustrate that a new car will never function at its full potential right from the start, and that a careful run-in period is advisable. This will avoid the need for unnecessary repairs or an improper consumption of oil, all of which will enable you to enjoy your vehicle to the full at a later stage once a higher mileage has been reached.