Have you become confused over the different types of diesel on the market today? No doubt the fuel formulas have undergone the greatest transformation in the last decade. Ranging from biodiesel, to low sulfur, the ULSD, to dyed and undyed. There may seem to be many choices and becoming informed may safe you the expense of making the wrong choice.

It used to be a trucker would have two choices, if any. Diesel #1 and diesel #2. These refer to the grades of diesel, which reflects the cetane content of the fuel. Cetane, like octane in gasoline, is the volatility of the diesel formula. Diesel #1 is more volatile but flows more freely, which works well in winter conditions. Diesel #2 is more lubricating and more viscous. Diesel #2 is used primarily for highway OTR semi trucks that benefit from lower operating temperature, extended rpm and torque used to pull loads. These benefits increase MPG and maintenance life of the engine. All diesel manufacturers recommend diesel #2 for normal highway use.

‘Winterized’ diesel fuels are comprised of a blend of diesel, kerosene, and light distillates that often results in reduced fuel economy. Although diesel engine manufacturers specifically warn against the use of additives, some products may provide the winterized protection needed without sacrificing MPG.

Premium diesel is typically a blend of diesel #1 and diesel #2 with detergent additives and lubricants. Most diesel manufacturers discourage use of premium diesel for highway use.

Biodiesel is the combination of organic and/or animal matter to produce a suitable alternative to petroleum products. Currently, biodiesel sold at a fuel retailer is a blend of up to 5% biodiesel to meet the manufacturers requirement. This is commonly known as B5 diesel fuel. However, most modern diesel engines have proven to run efficiently with up to a 30% biodiesel blend without modifications.

Low sulfur diesel #2 was the standard fuel for highway use prior to October 2006. Low sulfur diesel could not contain more that 500 ppm sulfur content. Low sulfur was continued in use for off road, agricultural, and marine applications until October 2014.

Ultra low sulfur diesel (ULSD) became available for commercial use in December of 2010 and as of October 2014 became the standard across the country for all diesel engines, including non road use diesel engines.

Generally speaking, all 2007 model and later diesel engines must use ULSD to be compliant. ULSD contains only 15 ppm sulfur content and with the use of today’s diesel engines using selective catalytic reduction (SCR) technology, their emissions are reducing harmful NOx into nitrogen and water, yet turning out more power and torque than ever before.