• Stock or Modified Engine (Less than 1,000 hp): For daily-driving diesels and modified trucks, we recommend the Signature Series 15W-40 Max-Duty Synthetic Diesel Oil (DME).

• Modified Engine (Up to 2,000 hp): Our DOMINATOR 20W-50 Competition Diesel Oil (DCO) is ideal for high-performance competition diesel trucks and diesel engines operating on the road.

• Modified Engine (More than 2,000 hp): For high-horsepower engines burning gasoline, alcohol, diesel, or methanol, the DOMINATOR 15W-50 Synthetic Racing Oil (RD50) offers superior performance. Please note that this oil is not intended for on-road daily driving.

If you're currently using 15W-40 and considering a switch to 20W-50, it's important to note that the 20W-50 oil provides a thicker film between engine components. This thicker film, especially beneficial for high-performance and modified engines, helps prevent metal-to-metal contact, particularly between bearings and the crankshaft. With increased power output in your truck, the oil endures greater pressure. A thicker oil film ensures better separation of components, contributing to prolonged engine life.

Absolutely. AMSOIL DOMINATOR 20W-50 Competition Diesel Oil represents the next evolution in protection and performance specifically tailored for modified, competition-grade diesel trucks. Making the switch ensures your engine receives optimal care and support, enhancing its longevity and performance.

When competing, it's crucial to use oil analysis to determine the most suitable drain interval. However, during non-competitive periods, you can either adhere to the original equipment manufacturer (OEM) drain intervals or extend them with the guidance of oil analysis. This approach ensures that your engine remains adequately lubricated and protected for prolonged periods, whether on or off the track.