Why it is best to let the engine idle for a while after a long journey

When driving, especially on the motorway or during sporty driving, the engine and turbo run at high revs. Temperatures rise, and components such as the turbo bearing need plenty of lubrication. If you switch off the engine immediately, the oil circulation stops while the turbo is still glowing or spinning. This can lead to the combustion of oil residues, carbon deposits and ultimately wear or even defects in the turbo.

The solution is simple but effective: let the engine idle for 1 to 2 minutes before turning it off. This allows the oil and coolant to continue circulating for a while and allows vulnerable parts to cool down in a controlled manner.

Some modern cars do this automatically with a so-called turbo timer, but in most vehicles, you as the driver have to remember to do this yourself.

Where should you leave the engine running?

It is important to think this through carefully. In many Belgian municipalities, it is prohibited to leave the engine idling unnecessarily. For example, waiting or parking at home is polluting and noisy. What this article recommends is something else: running the engine briefly after a journey, as part of technical aftercare, similar to coasting on a bicycle.

It is best to do this in a safe place off the public highway, such as:

• in a car park where you do not lock your car immediately,
• at a rest area along the motorway or petrol station where idling is temporarily permitted,
• or on your own property where local regulations allow this (some municipalities make exceptions for functional cooling phases).

Avoid running the engine unnecessarily for minutes on end in a residential area, in front of your house or on public roads if you are not driving anywhere, as this is punishable by law.