A new vehicle should be run in over a distance of 1,500 km. For the first 1,000 km the engine speed should not exceed 2/3 of the maximum permissible engine speed - do not use full throttle. From 1,000 to 1,500 km you can gradually increase the engine rpm and road speed.
During its first few hours of running, the internal friction in the engine is greater than later on when all the moving parts have bedded down.
How the vehicle is driven for the first 1,500 km also influences the engine quality. After this period you should continue driving at moderate engine speeds, in particular when the engine is cold. This helps to reduce wear and tear on the engine and increases the potential mileage which can be covered by the engine.