DIESEL FUEL LUBRICITY FACTS
I have recieved several questions regarding diesel fuel lubricity in today's low sulfur fuel. When the petroleum industry went to Ultra Low Sulfur Fuel there was extensive concern about the lack of lubricity that it would cause. It was then mandated that fuel contain a lubricity additive to meet the minimum specification. OK...so the question still remains, do we need to put something additional in?
I will list some interesting data on the lubricity of several fuels. The data represents typical values from an industry standard High Frequency Reciprocating Rig (HFRR) test with results measure by diameter of a wear scar in microns. Stay with me here. A lower number is better, less wear. Look at the different fuels from worst to best with the Manufacturers Recommended Level in as appropriate;
Typical Lubricity Test Result via HFRR - lower number is better HFRR(microns)
Ultra Low Sulfur (<15 ppm sulfur) #2 fuel no additive 540
Low Sulfur Fuel (<500 ppm sulfur)#2 fuel no additive 460
Engine Manufacturers Recommended Maximum 460
Premium Lubricity Additized Ultra Low Sulfur Fuel #2 420
Ultra Low Sulfur #2 fuel with 1% Biodiesel 320
Ultra Low Sulfur #2 fuel with 20% Biodiesel 315
Looking at the results you can see that adding Biodiesel to Ultra Low Sulfur fuel gives outstanding lubricity surpassing what can be claimed by marketed premium fuel brands. Interestingly, Biodiesel has its protective effect right away, increasing the concentration doesn't significantly lower the wear scar past the initial improvement.
Currently the state of MN mandates 5% biodiesel in #2 diesel fuel. This gives us excellent lubricity in all the fuel available in MN. I hope this sheds some light on fuel lubricity and how the use of biodiesel in our fuels can be very helpful.
