What is the maximum speed allowed for a vehicle during the break-in period?
2 Answers
The maximum speed for a new car during the break-in period is 70-80 km/h. Generally, during the break-in period, the engine speed should be controlled between 2000~4000 rpm, and high speeds and long-distance driving should be avoided. Therefore, it is not advisable to maintain a speed above 60 km/h for an extended period during the break-in period. After the total mileage reaches 500 km, the speed can be slightly increased. Precautions for the break-in period of a new car: 1. The break-in mileage for most vehicles is generally 1000-2500 km. The first 500 km is the initial break-in period, during which the speed should not be too fast, generally below 70-80 km/h, and the engine speed should not exceed 2200 rpm. The next 500-1000 km is the mid-term break-in period, during which the maximum speed can be appropriately increased, generally up to 90-100 km/h, with the engine speed still preferably below 2500 rpm. The final 1000-1500 km is the late break-in period, during which the speed can be increased to below 120 km/h. Since the break-in is a gradual process, it must be done step by step. The engine speed should not exceed 3000 rpm. 2. During the break-in period, it is best not to exceed 75% to 90% of the rated load capacity of the new car. Therefore, heavy loads should not be carried, and driving on poor road surfaces should be avoided to minimize significant bumps and reduce the vehicle's load.
The break-in period primarily requires controlling engine load, as speed is not the sole indicator. Having disassembled numerous engines during repairs, I've observed that aggressively broken-in piston rings exhibit particularly uneven wear. Focus on three key points: avoid sudden braking and rapid acceleration within the first 300 kilometers; refrain from fully loaded hill climbing within 1,000 kilometers; most crucially, keep the tachometer needle below one-third of the red zone. For instance, Japanese naturally aspirated vehicles can safely reach 110 mph, but for small-displacement turbocharged cars, this speed might generate excessive turbo pressure. Once, while inspecting a customer's Civic that exceeded speed limits during break-in, I found fine scoring marks on the cylinder walls.
