It's a Team's Life

Fuel Mileage Difference

Fuel Mileage Difference

By Sandy and Stephen
Posted Nov 7th 2022 8:00PM

Now that we are getting closer to colder weather and we will start seeing winterized diesel fuel.  So, why do diesel engines do not get as good fuel mileage running this winterized fuel over the non-winterized fuel?  Good question let us look into this and see if we can find the reason why this is.

All the refineries have to change diesel fuel to help it function better in cold and colder weather.  The change has to do with making the diesel have less sulfur and keeping it from gelling in the cold weather.  Taking more sulfur out gives diesel about three percent less energy so it takes the diesel engine more fuel to get more energy to move the vehicle down the road.  This equals less miles pre gallon out of winterized diesel fuel.

When the refineries remove sulfur this where we get ultra-low sulfur diesel (ULSD).  This process is what lowers the gelling temperature point of diesel to be used in the winter.  Beside removing sulfur refineries will also add/mix aromatic chemicals, naphtha, #1 kerosene to help reduce the gelling temperature of winterized diesel.  But these additives reduce the energy value of the diesel which then reduce your miles per gallon you get.  The normal British thermal unit (BTUs) for #2 diesel is 140,000.  Let’s take kerosene it has a BTU of 130,000 adding it to diesel will lower the BTU of diesel.  So, that will lower the total energy winterized diesel can produce.

So, is there you can do anything about increasing your miles per gallon using winterized diesel?  The short answer is “No”.  But would you give up a little fuel mileage to not have your diesel not gel and possibly leave you stranded on the side of the road or sitting in the truck stop parking lot.

Sandy & Stephen

Pinch Hitting for TeamCaffee