10 Best Synthetic Oil For Diesel Engines of December 2025
List of Top Rated Synthetic Oil For Diesel Engines from thousands of customer reviews & feedback.
Updated On Dec 2025
1,205 Reviews Studied
1
Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil (1-Gallon, Case of 3) Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Provides 1. 5% improved fuel economy performance compared to SAE 15W-40 oils
- Triple Protection Plus formula combines fully synthetic base oils with advanced additives for excellent equipment protection and long engine life
- Formulated with additive technology that protects against the effects of soot, dirt and other contaminants
- Engineered with shear stability to resist viscosity loss and maintain optimal engine oil pressure
2
Shell Rotella T5 Synthetic Blend 10W-30 Diesel Engine Oil (1-Gallon, Case of 3) Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Triple Protection Plus technology protects against wear, deposits and oil breakdown PLUS better fuel economy performance
- Fuel economy savings up to 1.6% compared to a conventional 15W-40, helping you stretch your budget and improve your bottom line
- Provides excellent wear protection, which keeps engines running longer
- Better cold cranking properties and better low temperature pumpability than conventional 15W-40, it reaches critical engine parts faster in colder temperatures to minimize wear and makes hard work easier in harsh climates
- Extended drain capabilities
4
Shell Rotella T - 550045348 5 Synthetic Blend 15W-40 Diesel Motor Oil (1-Gallon, Single-Pack) Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Advanced low-ash formulation helps control the blocking or poisoning of exhaust after treatment devices, helping maintain vehicle emission compliance and engine fuel efficiency.
- Synthetic base oil components provides the capability to improve cold starting and low temperature performance reduce fuel consumption
- The Advanced formulation delivers good engine cleanliness and protection against piston deposits ensuring engine and component reliability at extended oil drain intervals.
- Rotella T5 meets the requirements of the major US engine manufacturers for low emission applications.
5
Lucas Oil 10299-PK4 Synthetic 15W-40 CJ-4 Truck Oil - 1 Gallon Jug, Pack of 4 Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
6
Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil (1 Gallon, Case of 3) Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Triple Protection Plus technology protects against wear, deposits and oil breakdown plus provides better low temperature flow compared to SAE 15W-40 oils
- Helps control engine deposits for reliability at extended oil drain intervals
- Formulated to control engine wear, 37% better than the maximum wear requirements in API CK-4 engine wear tests
- Heavy duty engine oil formulated with synthetic base oil components
- Delivers improved oxidation performance for increased resistance to breakdown under high temperatures compared to the previous formulation
7
Mobil 1 Turbo Diesel Truck Full Synthetic Motor Oil 5W-40, 1 Gal Read Review
- Mobil 1 Turbo Diesel Truck is designed for modern diesel truck engines, delivering long drain capability, exceptional performance, and potential fuel economy benefits*
- Meets or exceeds the demanding specifications of major truck manufacturers - one engine oil can be used for mixed fleet operations
- Recommended for use in all super high-performance diesel applications, including low emission engines
- Helps engines last longer by reducing low-temperature sludge buildup and high-temperature deposits
- Exceptional low-temperature pumpability allows for easy engine start-up and helps to reduce wear
8
Valvoline Premium Blue Extreme SAE 5W-40 Full Synthetic Diesel Engine Oil 1 GA, Case of 3 Read Review
- “The Only One“ endorsed and recommended by Cummins
- Superior synthetic base stocks provide faster, safe starts during freezing weather and enhanced thermal properties for hot weather operations
- Outstanding oxidation resistance supports long oil life in heavy duty engines
- Superior wear protection for hardworking heavy-duty trucks and equipment
9
Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil (1-Gallon, Case of 3) Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Provides 1. 5% improved fuel economy performance compared to SAE 15W-40 oils
- Triple Protection Plus formula combines fully synthetic base oils with advanced additives for excellent equipment protection and long engine life
- Formulated with additive technology that protects against the effects of soot, dirt and other contaminants
- Engineered with shear stability to resist viscosity loss and maintain optimal engine oil pressure
- Suitable for diesel-powered vehicles from tractor/trailers to classic cars and heavy-duty diesel pickups that allow an SAE 5W-40
- Part Number: 550045347-3PK
10
Shell Rotella T5 Synthetic Blend 10W-30 Diesel Engine Oil (1-Gallon, Single Pack) Read Review
- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Advanced low-ash formulation which helps control blocking of or poisoning of exhaust after treatment devices
- Rotella T5 use of synthetic base oil components provides the capability to improve cold starting and reduce fuel consumption and save money, without compromising engine protection or durability
- Rotella T5 advanced formulation delivers good engine cleanliness and protection against piston deposits ensuring engine and component reliability at extended oil drain intervals
- Shell Rotella T5 meets the requirements of the major US and European engine manufacturers for low emission applications