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Sinclair Full Synthetic Heavy Duty Diesel Engine Oil

Heavy Duty Engine Oil

Sinclair delivers outstanding protection that stands up to even the toughest conditions.

Full Synthetic Heavy Duty Diesel Engine Oil

Sinclair Full Synthetic Heavy-Duty Diesel Engine Oil is specifically formulated to give you optimal protection and performance from our most advanced technology.

Built for the Engines They're Building Today

Today’s engine designs have progressed and put new demands on engine oil, as OEMs increase horsepower and engine heat, reduced emissions, and increase fuel economy. Sinclair Heavy Duty Diesel Engine Oil has progressed as well. It takes the most advance engine oils to meet the demands of balancing durability, extending drain intervals, and protecting emissions control devices, and Sinclair delivers performance you’ll notice.

Heavy-Duty Protection

Sinclair Full Synthetic Heavy Duty Diesel Engine Oil gives outstanding protection and provides powerful, long-lasting, high-performing friction management and reduced metal-to-metal contact.

Sinclair Full Synthetic Heavy Duty Engine Oils: Performance You'll Notice

Our Full Synthetic oils have been specifically formulated and designed to provide:


  • Improved fuel economy. Reduces fuel costs without sacrificing engine protection and performance.
  • Extended oil drain intervals. Fuel economies can be gained when following engine manufacturer recommendations and in conjunction with scheduled oil analysis.


  • Enhanced friction reduction. Provides a very strong oil film to prevent metal-to-metal contact between rotating parts, delivering up to 53% better wear protection.1
  • Unsurpassed wear protection. The latest generation API CK-4 Sinclair engine oils provide increased protection against harmful engine and bearing wear due to cavitation, because they improve oil aeration.

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  • Better oxidation and deposit control. Stands up to high heat and stress to protect as well on the last day as it does on the first day. Up to 83% better oxidation control and 63% better deposit control.2
  • Provides added oxidation control and protection against acid buildup that can cause rust and corrosion.

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1 Using HD 10W-30 CK-4, compared to Conventional HD 15W-40 CK-4 during on-highway long-haul service. Savings will vary on idle time and other driving conditions of your fleet or vehicle.

2 Compared to new limits of API CK-4 requirements.

Sinclair Full Synthetic Heavy Duty Diesel Engine Oil

Sinclair Full Synthetic 5W-40 CK-4 Heavy Duty Diesel Engine Oil

For superior fuel economy, wear protection and piston deposit control.

Product Details