Definition
To 'run in' a new vehicle, you operate it cautiously at low speeds initially, to ensure the longevity and integrity of the engine.
With our new car, we decided to drive slowly for the first few hundred kilometers to run the engine in.
To ensure optimal performance, the factory conducts a thorough run-in of the machinery before it leaves the production line.
Following the dealer's advice, he carefully ran in his new electric car.