How long does it take for a new car to break in before it can be driven on the highway?

[McJoy]

A new car can be driven on the highway at any time during the break-in period. Precautions for driving on the highway include: 1. The driver and front-seat passenger should fasten their seat belts, and the driver should not answer phone calls; 2. Avoid sudden steering wheel movements while driving at high speeds; 3. Do not change lanes arbitrarily while driving. When changing lanes or overtaking the vehicle in front, the turn signal must be activated in advance; 4. When overtaking, only the adjacent lane is allowed. After overtaking, the vehicle should immediately return to the driving lane and must not straddle or drive on the lane divider; 5. Do not reverse, drive in the opposite direction, cross the central divider to make a U-turn or turn, conduct test drives, or drive a training vehicle. Overtaking and parking on ramps are prohibited; 6. Maintain a following distance of at least 100 meters. When the speed is below 100 km/h, the distance from the vehicle in front in the same lane can be appropriately reduced, but the minimum distance should not be less than 50 meters.

[ODominic]

About breaking in a new car, my friend who's been a technician at a 4S dealership for over a decade says modern manufacturing technology has improved significantly. Just pay attention during the first 1,000 kilometers. For the initial 500 km, the piston rings are still seating, so avoid exceeding two-thirds of the tachometer's redline. On highways, don't constantly cruise at 120 km/h - vary speeds periodically to break in all transmission gears. Most crucially, avoid sudden braking or aggressive acceleration to ensure even bedding of brake rotors and pads. I remember after my new car's first highway run, the technician showed me all the metal particles collected on the oil pan magnet during maintenance!

[OAdriel]

Last time when I accompanied my colleague to pick up his new car, the salesperson specifically explained that the break-in period is divided into three stages: the first 300 kilometers are the most critical, as the tires and brakes haven't fully settled in yet. Driving at high speeds during this phase causes excessive temperature fluctuations in the tires, which can damage the rubber. From 500 to 1,000 kilometers, you can gradually increase speed, but it's best to keep the engine RPM below 4,000. Actually, the new car manual states it very clearly. The manual for my German car mentioned avoiding cruise control within the first 1,600 kilometers to allow all components to fully adapt to different operating conditions. Later, during the first maintenance, I specifically asked the service supervisor, and he said that nowadays new cars undergo cold break-in at the factory. The main thing is to avoid prolonged high-load conditions.

[VonPaisley]

Breaking in a car on the highway isn't as scary as it seems—the key lies in the driving technique. During the initial break-in period, I make it a habit to actively vary my speed every 20 minutes when driving on highways: cycling between 80 and 110 km/h several times to ensure proper gear meshing in the transmission. I drive gently until the oil temperature reaches 90°C, then gradually increase engine load once the coolant temperature stabilizes. Last time when I drove a friend's hybrid to a neighboring city, an engineer advised alternating between EV and HEV modes, explaining that the battery management system also needs data adaptation.