Seasonal Diesel Fuel and Fuel Additive Lubricity Survey Using the “Munson ROCLE” Bench Test

The Munson Roller on Cylinder Lubricity Evaluator (M-ROCLE) developed at the University of Saskatchewan was used for this survey. Dimensionless Lubricity Numbers (LN), based on wear scar areas and friction coefficients, were employed to evaluate the test fuels and additives. The Canadian seasonal winter and summer, low sulfur diesel fuels were generally found deficient in lubricity (LN<1) on the Munson ROCLE bench test. The locally marketed summer fuels were found to average lower in lubricity than the winter fuels. A number of popular commercial diesel fuel additives were tested and the majority were found to improve the unadditized reference winter diesel fuel lubricity. The most cost effective lubricity additive surveyed was a bio-based product. The overall Lubricity Number coefficient of variation of the individual M-ROCLE data of approximately 5.3% indicated high test precision.