The cold season is not only hard on human immunity, but also on our vehicles. When the frost starts to appear outside every morning, it’s a very difficult time for the car. Drivers are often faced with the dilemma of whether to leave the engine running for a while or sit down and drive straight away, unless of course the car is frozen and starts. What is the right decision? What course of action should we take in winter so that we don’t lead our four-wheeled darling’s engine to a slow death?

A cold start of a motor vehicle is very dangerous for the machine. The oil and other fluids are significantly cold, the temperature at that moment is far below the optimum operating value. The fuel that flows into the cylinders can condense on their cold walls. This impairs combustion and leads to deposits of particles that bind to the lubricant. Modern research shows that emission production at this stage can be extremely high. During a cold start, CO emissions can exceed normal values by hundreds of percent.

Cold start as a major problem

From an emissions and environmental perspective, cold start is particularly problematic. Some studies suggest that the proportion of emissions generated during start-up can account for 10 to 30 % of the total emissions of a vehicle in normal operation. If the ambient temperature is lower, the emissions increase can be dramatic.

However, drivers still have a strategy known as “start and go”. While there are advantages to this, on the other hand, starting a car quickly in winter carries a number of risks. Not only for the environment, but also for the car itself.

Before you turn the key in the ignition in winter, you need to make sure your car can handle the cold weather start. ━━ Before you turn the key in the ignition in winter, you need to make sure your car can handle the cold weather start. ( Source: Ivan Shemereko /  Unsplash+ )

Risks for the car

When the engine is running but not fully warmed up, lubrication is weaker and some moving parts may not be lubricated sufficiently. This can lead to higher friction and micro wear. Some sources even state that some engine wear occurs during the first few minutes of operation after a cold start, when the engine is most vulnerable. In addition, excessively fast or “wild” driving during this phase can accelerate wear and load on bearings, pistons and other parts.

If the engine is regularly subjected to cold starts, many small damages accumulate. This can manifest itself in a gradual reduction in efficiency, higher oil consumption, carbon deposits, deterioration of compression or leaking piston rings. For some engines, even a significant difference in oil quality or lubricant type can mean tens of thousands of miles of service life.

Some sources make the extreme claim that one cold start at an ambient temperature of around -5 °C can cause wear equivalent to about 99.2 km. Such figures should be taken with a pinch of salt, but they underline the fact that even a single start is not “free”. Over a long period of time, frequent cold starts can cause an engine that was healthy during normal operation to show signs of wear over time.