Best Diesel Engine Oil 15w40

Check out our product review of the best diesel engine oil 15w40. We tried 10 models and can tell you the absolute best varieties.

In Hurry? Checkout Our Top Pick Of Best Diesel Engine Oil 15w40.

Our Top Pick
Valvoline Premium Blue SAE 15W-40 Diesel Engine Oil 1 GA

9.7/10 our score

Best Diesel Engine Oil 15w40

Rank Product Name Score
1
Valvoline Premium Blue SAE 15W-40 Diesel Engine Oil 1 GA

Valvoline Premium Blue SAE 15W-40 Diesel Engine Oil 1 GA
9. 7
2
Mobil Super 96819 15W-40 Delvac 1300 Motor Oil - 1 Gallon (Pack of 4)

Mobil Super 96819 15W-40 Delvac 1300 Motor Oil – 1 Gallon (Pack of 4)
9. 5
3
Delo 400 SDE SAE 15W-40 Motor Oil - 1 Gallon Jug, (Pack of 3)

Delo 400 SDE SAE 15W-40 Motor Oil – 1 Gallon Jug, (Pack of 3)
9. 1
4
Shell Rotella T - 550045348 5 Synthetic Blend 15W-40 Diesel Motor Oil (1-Gallon, Single-Pack)

Shell Rotella T – 550045348 5 Synthetic Blend 15W-40 Diesel Motor Oil (1-Gallon, Single-Pack)
8. 8
5
Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil (2.5 Gallon, Single Pack)

Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil (2.5 Gallon, Single Pack)
8. 6
6
Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil (1-Gallon, Single Pack, New Packaging)

Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil (1-Gallon, Single Pack, New Packaging)
8. 2
7
Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil (1 Gallon, Case of 3)

Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil (1 Gallon, Case of 3)
8. 0
8
Schaeffer Manufacturing Co. 0700CK4-012 SynShield Durability Advantage 15W-40 Diesel Oil, 12 Quart, Bottle (Pack of 12)

Schaeffer Manufacturing Co. 0700CK4-012 SynShield Durability Advantage 15W-40 Diesel Oil, 12 Quart, Bottle (Pack of 12)
7 .7
9
Delo 257004470 400 XLE SAE Synblend Synthetic Blend Oil 15W40

Delo 257004470 400 XLE SAE Synblend Synthetic Blend Oil 15W40
7. 4
10
Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil (1-Gallon, Case of 3)

Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil (1-Gallon, Case of 3)
7. 2

1. Valvoline Premium Blue SAE 15W-40 Diesel Engine Oil 1 GA

Valvoline Premium Blue SAE 15W-40 Diesel Engine Oil 1 GA

9.7/10 our score

  • One Solution Technology suitable for a wide range of heavy-duty engines including diesel, gas and natural gas applications
  • “The Only One“ endorsed and recommended by Cummins
  • Outstanding oxidation resistance supports long oil life in heavy duty engines
  • Superior wear protection for hardworking heavy-duty trucks and equipment

2. Mobil Super 96819 15W-40 Delvac 1300 Motor Oil – 1 Gallon (Pack of 4)

Mobil Super 96819 15W-40 Delvac 1300 Motor Oil - 1 Gallon (Pack of 4)

9.5/10 our score

  • For best performance, follow the manufacturer’s recommendations in your vehicle owner’s manual.

3. Delo 400 SDE SAE 15W-40 Motor Oil – 1 Gallon Jug, (Pack of 3)

Delo 400 SDE SAE 15W-40 Motor Oil - 1 Gallon Jug, (Pack of 3)

9.1/10 our score

  • For best performance, follow the manufacturer’s recommendations in your vehicle owner’s manual.
  • Premium quality, heavy duty motor oil manufactured in the USA
  • Formulated to meet the requirements of post-2007 low emission engines
  • Provides outstanding performance with ultra-low sulfur diesel and also with normal and low sulfur diesel fuels
  • May be used in older, conventional engines and gasoline engines
  • Formulated with ISOSYN technology
  • Reduced operating costs
  • Enhanced emission control system life
  • Reduced inventory costs
  • Warranty plus protection
  • 1 gallon

4. Shell Rotella T – 550045348 5 Synthetic Blend 15W-40 Diesel Motor Oil (1-Gallon, Single-Pack)

Shell Rotella T - 550045348 5 Synthetic Blend 15W-40 Diesel Motor Oil (1-Gallon, Single-Pack)

8.8/10 our score

  • 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. Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil (2.5 Gallon, Single Pack)

Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil (2.5 Gallon, Single Pack)

8.6/10 our score

  • For best performance, follow the manufacturer’s recommendations in your vehicle owner’s manual.
  • Formulated for enhanced deposit protection to help keep engines cleaner over the oil drain interval
  • Exclusive low ash formulation helps protect the exhaust catalysts and particulate filters found on the latest low emission vehicles
  • Meets or exceeds API CJ-4 requirements, and is designed to provide extra performance Shell Rotella T4 performs well in both older and new engines
  • Enhanced shear stability performance for viscosity control and optimal oil pressure in your engine
  • Provides outstanding protection for virtually all heavy duty diesel engines, including the latest emission controlled engines using EGR and containing a Diesel Particulate Filter

6. Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil (1-Gallon, Single Pack, New Packaging)

Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil (1-Gallon, Single Pack, New Packaging)

8.2/10 our score

  • For best performance, follow the manufacturer’s recommendations in your vehicle owner’s manual.
  • Better fuel economy – compared to 15W-40 oils Rotella offers enhanced fuel economy capability of 1. 5% without compromising engine protection or durability
  • Improved wear performance – provides a significantly increased level of protection against harmful engine wear when compared to previous generation API CJ-4 engine oils
  • Improved deposit control – advanced multi-functional dispersant additives in combination with synthetic base oils provide an enhanced level of protection against the effects of soot, dirt and other contaminants
  • Emissions system compatibility – advanced low-ash formulation helps control blocking of or poisoning of exhaust after-treatment devices, helping maintain vehicle emission compliance and engine fuel efficiency
  • Improved heat resistance – resists breakdown by heat to provide continuous protection throughout the service interval

7. Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil (1 Gallon, Case of 3)

Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil (1 Gallon, Case of 3)

8/10 our score

  • 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

8. Schaeffer Manufacturing Co. 0700CK4-012 SynShield Durability Advantage 15W-40 Diesel Oil, 12 Quart, Bottle (Pack of 12)

Schaeffer Manufacturing Co. 0700CK4-012 SynShield Durability Advantage 15W-40 Diesel Oil, 12 Quart, Bottle (Pack of 12)

7.7/10 our score

  • Excellent wear protection during severe operating conditions
  • Oil durability: strong oxidation and viscosity control with less oil consumption
  • Better contamination control with superior soot-busting, deposit-dispersing capability
  • Strong stay-in-grade performance throughout the life of the oil
  • Friction modified with micron moly and penetrate

9. Delo 257004470 400 XLE SAE Synblend Synthetic Blend Oil 15W40

Delo 257004470 400 XLE SAE Synblend Synthetic Blend Oil 15W40

7.4/10 our score

  • For best performance, follow the manufacturer’s recommendations in your vehicle owner’s manual.
  • A premium synthetic blend, long drain  mixed-fleet engine oil specifically formulated for on- highway applications, including 2017 greenhouse gas (GHG 17) compliant diesel engines
  • Isosyn Advanced Technology: The Next Generation of Heavy Duty Engine Oil Chemistry – engineered to deliver longer oil life, better wear protection and longer engine life
  • Isoclean: Certified clean – ensure your lubricants meet OEM cleanliness requirements to help you minimize downtime, reduce maintenance costs and extend equipment life
  • Provides high performance piston deposit control and turbocharger protection due to its superb oxidation performance. Its high performing detergent and dispersant additives provide excellent diesel engine component protection.
  • Exceptional soot dispersancy and wear control – Cylinders, pistons, rings, and valve train components are well protected against wear and corrosion, providing optimum service life and minimal maintenance, contributing to maximum equipment utilization and minimal downtime.

10. Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil (1-Gallon, Case of 3)

Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil (1-Gallon, Case of 3)

7.2/10 our score

  • 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