10 Best Motor Oil For Diesel Engines of August 2025

List of Top Rated Motor Oil For Diesel Engines from thousands of customer reviews & feedback.

Updated On Aug 2025

776 Reviews Studied

By Customer Ratings

1
Image
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.

2
Image
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

3
Image
Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil (1-Gallon, Single Pack, New Packaging) Read Review

  • 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

4
Image
Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil (2.5 Gallon, Single Pack) Read Review

  • 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

5
Image
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

6
Image
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

7
Image
Valvoline Premium Blue SAE 15W-40 Diesel Engine Oil 1 GA, Case of 3 Read Review

  • 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

8
Image
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

10
Image
Delo 257004470 400 XLE SAE Synblend Synthetic Blend Oil 15W40 Read Review

  • 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.