Almost all manufacturers recommend certain guidelines for the running-in (also known as break-in) period of a car. A break-in period is defined as the initial time during which the moving parts in the machinery establish a stable relationship and settle properly. It’s also recommended in case of cars and it’s recommended for the sake of longevity and reliability of the car’s engine.
For the exact length of duration of break-in period, refer to the owner’s manual. It generally varies from 1000-1500kms. Here is a list of things that you should keep in mind.
Don’t floor the throttle
In case of petrol, the throttle is controlled by an air intake valve (except if it is a direct injection engine) and in case of diesel it’s controlled directly by the amount of diesel that’s sprayed inside the cylinder. Regardless of the way it’s done, when you floor the throttle the engine burns more fuel and more quickly. It’s advisable to operate the engine with part throttle or gentle throttle during the running in period.
Don’t shift at redline
A gearshift that comes at the right time would reduce load on the engine. Even the tightest tolerances achieved through super finishing operations like honing, lapping etc. does not provide the perfect fit for piston and cylinder. Therefore, during the running-in period, to ensure that you don’t strain the engine, it’s advisable to shift the gears without revving it all the way to the red line. The revs of the engine should rise sufficiently enough for the higher gear, so that you do not lug the engine and put excessive strain on the transmission either. This would result into finely-glazed uniform surfaces that would provide superior engine life.
Don’t drive at constant load
The break-in in for high-performance sports cars is generally done at the factory itself. Therefore, these cars can be driven straight on the track after delivery. According to the experts, the break-in is done best with a modulating load and it’s best to drive in different gears and varying rev range.
Therefore, it’s recommended that you do not use the cruise control or drive the car at one speed for long interval. It’s likely a condition that you would experience on highway, therefore, it’s better to drive within the city for first few thousand kilometres.
Don’t tow another car
As mentioned previously, a successful break-in requires varying operating temperatures / conditions for the engine and moderate loads. Operating engine continuously at higher rev ranges should be avoided. However, in case of towing, the engine would need to work really hard, and it goes without saying that it should be avoided for the first 1500kms or so.
Don’t run it cold
Metal expands as it gets heated. All engines and parts are designed to work at optimum working temperature. When you start the engine, it’s cold and different parts take some time to reach working temperature. Damage caused due to warpage would be excessive if engine is not allowed to reach working temperature. Allow the engine to idle for a minute or so before putting in the gear and driving away. The engine would not heat up within one minute time, however, until the time it comes to proper working temperatures avoid pushing too hard and drive leisurely. In fact this practice should be followed for the entire life duration.
A proper break-in would not only affect the longevity and reliability of the engine. It’s believed that it also affects the fuel-efficiency to some extent. Another important and critical event is the first oil change that should be done as recommended by the manufacturer.