24 November 2014

Subzero temperatures are coming – fill your fuel tank with winter grade diesel


Winter is, slowly but surely, coming to Finland. It's time to start using winter grade diesel. Neste Oil's Technical Expert Tuukka Hartikka replies questions about winter diesel.

When should you start using the winter grade?

You should start refueling your car with the winter grade as soon as possible, i.e. as soon as the winter grade is available. You should make sure that your fuel tank is as empty as possible when refueling winter diesel for the first time to make sure that the summer grade diesel will soon leave the fuel system. Mixing winter grade with summer grade will clearly deteriorate the cold weather characteristics of the winter grade diesel.

What are the differences between winter and summer grades?

They differ from each other in their cold weather characteristics, i.e. their cloud point and filterability point. Cloud point means the lowest temperature at which a fuel can be stored and filterability point the lowest operating temperature at which the vehicle should still run if properly serviced. There are differences between the lowest operating temperature of car models, however, which is why cloud point is more important. It states the temperature at which cars – regardless of their age and model – will run.

How do you know that your local service station is currently selling winter grade diesel?

The cloud point and filterability point can usually be found on a sticker next to the fuel pump. The cloud point of regular Neste Oil winter grade diesel (–29/–34°C) is –29°C and its filterability point is –34°C. The cold weather characteristics of Neste Pro Diesel, which contains renewable NEXBTL diesel, are better than those of regular winter diesel. The cloud point of the winter grade of Neste Pro Diesel (–32/–37°C) is –32°C and the filterability point is –37°C. Selected stations in northern Finland also sell arctic diesel for extremely cold conditions (–40/–44°C).

Why not use winter grade all year round?

You could use winter grade also in the summer, but that is not cost-efficient. When refining crude oil, you get much less winter grade diesel than summer grade diesel, which would lead to problems with the availability of the winter grade. Furthermore, the energy content of fossil winter grade diesel is somewhat lower than that of summer grades.

What else should you take into account in terms of your car in the winter?

You should make sure that your fuel filter and fuel system are in good condition. Whenever possible, you should take care of the replacement and annual service of your fuel filter during the fall. You should preheat your engine in the wintertime to make sure that it will be subjected to as little stress as possible. In addition, a preheated engine will produce less emissions when started and reduce the fuel consumption.