Your diesel trucking fleet faces demanding highway conditions and tight deadlines. Dennis Oil Company protects your equipment and keeps you on the road with dependable heavy-duty lubricants backed by the latest technological advances. We also supply critical lubricants to agriculture, mining, and heavy construction companies.
Dennis Oil Company’s Kleen-Tech™ heavy-duty diesel engine oils provide outstanding performance. In fact, our unique formula actually improves oil properties over time. It retains its viscosity, for long-lasting anti-friction and anti-wear benefits – even in today’s hotter engines.
Semi-truck engine manufacturers continuously advance and update engine designs, so we keep enhancing our Kleen-Tech technology.
Dennis Oil Company’s advanced heavy-duty diesel engine oils meet the difficult challenges of endurance and fuel economy while extending drain intervals and reducing emissions.
Our heavy-duty diesel engine oils are available in conventional, semi-synthetic, full-synthetic, and premium-blend to provide extra engine protection.
Kleen-Tech 15/40 API CK-4, SN, Formulated to meet or exceed all major brands.
Fleet 15/40 API CK-4, SN, Formulated to meet or exceed all major brands.
Fleet 30, 40 API CF 2-cycle diesel engines (Detroit), hydraulics of heavy equipment 1994 and older, newer to TO-4.
Magnum 30, 40 API CF, Additional additive package (zinc, detergent, etc.) 2 cycle diesel engines (Detroit) hydraulics of heavy equipment 1994 and older, newer TO-4 fluids
NGEO Low Ash 15/40 Meets API CF, CD-natural gas engine calling for .5 ash content.
Kleen-Tech 10/30 API CK-4, Cummins approved, synthetic blend, formulated to meet or exceed all major brands.
Kleen Tech Syn Blend 15/40 API CK-4, Formulated to meet or exceed all major brands.
Magnum XD 15/40 API CK-4 additional additive package for additional soot protection, great for off-road applications, exceeds all major brands.
Magnum XD 10/30 API CK-4, synthetic blend additional additive package for additional soot protection, exceeds all major brands.
Heavy-Duty SYN 5/30 meets API CK-4-fully synthetic heavy-duty engine oil, provides additional fuel savings.
Magnum XL 5/40 Meets API CK-4, SN, fully synthetic, exceeds all major brands, provides additional fuel savings.