Palm oil biodiesel has been a sustainable and renewable alternative to petroleum since the 1980s. Palm biodiesel was gradually blended with petroleum diesel to introduce environmentally friendly fuels into the Malaysian market. Consumers sought additional information to assess the potential risks of higher palm biodiesel blends. Six diesel trucks under actual on-road conditions were involved in using palm B20 and B10. Fuel economy for the B20 vehicles was 2.020 km L^–1 and for B10 vehicles was 1.910 km L^–1. Idling adjusted fuel economy for the B20 vehicles was 2.107 km L^–1 and for B10 vehicles was 2.055 km L^–1. Statistical analysis indicated no significant difference in fuel economy, vehicle payload affecting fuel economy, or maintenance costs between the B20 and B10 groups. Engine oil samples, taken at 5,000 km intervals, were tested to determine the impact of using the B20 blends. All engine oil samples were found to remain within operational service limits. B20 usage positively impacted engine oil quality with higher total basic number and lower iron content than B10. Statistical analysis demonstrated insignificant differences between the two fuel groups in fuel economy, idling adjusted fuel economy, payload, service cost, viscosity, zinc, sodium, soot in oil and magnesium, with a high degree of confidence.