Your diesel engine does not start in winter. What can be the reason for this?

A diesel engine not starting in winter can be due to several reasons, and it's important to consider the factors affecting fuel performance in cold weather. In this case, if summer diesel is still in the tank, it can gel or thicken in colder temperatures, preventing the engine from starting.

In Germany, using the appropriate fuel for the season is legally mandated to ensure vehicle reliability and safety. It's essential to switch to winter diesel, which is formulated to remain fluid in lower temperatures.

Though issues like wet ignition cables or faulty spark plugs can affect gasoline engines, they do not apply to diesel engines. Thus, while you recognized the issue with summer diesel correctly, understanding that multiple factors can lead to starting problems reinforces the importance of using the right fuel in relation to traffic rules and vehicle maintenance.