I add some. However, I had left over 2 stroke oil and it gave me something to do with it. Since is is supposed to reduce the "wear scar" it is a good thing.
See post #13 for cart Spicer Lubricity Test. The shorter the blue bar on the chart means less "Wear Scar". Note where 2% Biodiesel falls on the chart.
2 Stroke Anyone?