Shell Rotella T6

Diesel engine oil: Product Spotlight

June 26, 2023
Here's a look at the latest offerings in engine oils to keep trucks humming along the highways.


Amsoil has a complete line of diesel engine synthetic oils. The line features the Signature Series Max-Duty Synthetic in 5W-40, 5W-30, 10W-30, 15W-40, and 0W-40 grades. The line also includes Heavy-Duty Synthetic in 15W-40, 5W40, 10W-30 blends. The oils feature extreme-pressure protection and six times more wear protection while maintaining viscosity, maximizing fuel efficiency, and minimizing oil consumption. The Signature Series performs well in extreme temperatures. Amsoil also carries a line of filters, diesel additives, and injection cleaners.


CastrolCastrol’srange of diesel engine oils are formulated to deliver a high level of engine protection throughout service intervals, which can help save on maintenance costs and repairs and reduce downtime. Castrol diesel oils extend drain intervals, validated by a used oil analysis program like Castrol Labcheck, improve fuel efficiency, can be used in diesel and natural gas-fueled engines, and provide anti-wear protection and high resistance to acid corrosion. Castrol engine oils meet—or exceed—OEM specifications for Caterpillar, Cummins, Detroit Diesel, Mack, and Volvo.

See also: Fluid analysis is more important than ever


CenexCenextouts that its heavy-duty diesel engine oils deliver dependable protection in the toughest conditions. Cenex’s Maxtron Enviro-EDGE and Maxtron DEO are formulated with EnduroVis star polymer technology for durability and improved engine performance. The company’s Superlube TMS para-synthetic is a mixed formulation of conventional and synthetic base oils, which provides field-tested engine durability, better protection against soot, and prevents oil thickening. Cenex says it’s appropriate for dirty, dusty, and heavy load conditions. Superlube 518 is enhanced diesel engine oil formulated for older diesel and gasoline engines calling for a low-ash straight grade oil.


FiveChevronproducts for on-highway heavy-duty applications include Delo 600 ADF, an Omnimax synthetic engine oil that improves engine and aftertreatment system life; Delo 400 XSP, another synthetic, with Isosyn advanced full synthetic technology that improves valvetrain and piston ring wear protection; Delo 400 XLE and ZFA, an Isosyn synthetic that increases scuffing resistance and protection against light-duty power cylinder failure by reducing low-speed pre-ignition events; Delo 400 SDE, a conventional oil that reduces cam and power cylinder wear; and Delo 400 SNG, which provides wear protection and is rated for sludge and deposit control. Chevron also makes Delo 400 and 600 formulations for vocational and off-highway applications.


CitgoCitgo'sCitgard 700 synthetic blend engine oils deliver the performance needed for newer engine designs while improving performance in older engines, according to the company. Citgard 700 synthetics are engineered with a proprietary additive technology that protects engines running at higher operating temperatures and fuel injection pressures while meeting tighter wear limits and lower emission requirements. SAE 10W-30 viscosity grade assists in attaining the new Phase II fuel efficiency standards by improving fuel economy, increasing cold startup lubrication, and providing engine durability.

Hot Shot's Secret

Hot Shot’s Secret10w-30 Blue Diamond PAO diesel engine oil from Lubrication Specialties Inc. utilizes 100% poly-alpha-olefin (PAO) Group IV synthetic oil and high-quality Group V esters for a 100% synthetic formula. By using 100% synthetic Group IV and Group V base oils, a robust CK-4 additive package, and the infusion of patented FR3 nano lubricant technology, Blue Diamond PAO 10w-30 oil provides longevity and performance. Benefits include improved starting, increased power and fuel economy, reduced soot, extended engine life, and reduced friction.

Mobil Delvac/Exxon Mobil

Mobil Delvacoils from Exxon Mobil help protect diesel engines with a full line of blends for a variety of power plants and operating conditions. Mobil Delvac Extreme, for example, features a boosted formulation that meets or exceeds the API CK-4 specification and provides enhanced engine protection, even in extreme conditions. Mobil Delvac 1300 Super does the same. Mobil Delvac Extreme FE provides extended drain capability and meets or exceeds the API FA-4 specification for fuel-efficient engine oils. Mobil Delvac Modern CNG/LNG is formulated specifically for spark-ignited, natural gas-fueled stoichiometric and lean-burn engines. Mobil Delvac HDEO meets warranty requirements for high-speed, four-stroke heavy-duty diesel engines and is said to deliver an average of up to 30% more wear protection versus CK-4 requirements.

Phillips 66

Phillips 66heavy-duty diesel engine oil is a universal fleet engine oil designed for use in on-highway diesel trucks and off-highway diesel equipment operating in moderate to hot climates. It provides soot control to protect against abrasive wear and soot-induced oil thickening, resistance to viscosity and thermal breakdown at high temperatures, protection against sludge and varnish formation, high shear stability, protection against rust and bearing corrosion, and good resistance to foaming and aeration. Phillips 66 engine oil is appropriate for older diesel equipment with conventional, non-EGR (exhaust gas recirculation) engines; mixed fleets with both diesel and gasoline-fueled vehicles; and off-highway construction, earth moving and mining equipment. Guardol FE (formerly known as Triton FE) is a Phillips 66 full synthetic engine oil developed for fuel economy benefits in 2017 and newer engines where FA-4 is specified. Guardol FE is formulated with high-quality synthetic base stocks and a proprietary low-SAPS additive package to provide engine protection in diesel engines specifying FA-4. The additive provides increased engine protection of critical engine parts.

Shell Rotella

Shell RotellaShell Lubricants’Shell RotellaT6 10W-30 is a full synthetic heavy-duty engine oil. A full synthetic 10W-30 provides the benefits of a full synthetic engine oil in the fastest-growing viscosity grade for diesel-powered vehicles. The versatile oil offers fuel economy benefits and improved engine protection for hard-working trucks. Shell Rotella T6 10W-30’s unique formulation is designed to provide better wear performance compared to conventional and synthetic blend Shell Rotella 15W-40 and 10W-30 products while also delivering improved fuel economy capability of 2% compared to SAE 15W-40 heavy-duty engine oils. This can save money in fuel consumption without compromising engine protection or durability. The oil also helps ensure enhanced engine protection and can help to reduce maintenance costs.

See also: Shell Starship transitioning to natural gas


ValvolineValvolinePremium Blue heavy-duty engine oil features proprietary One Solution GEN2 technology designed to protect hard-working diesel, gasoline, and natural gas engines in both on-highway and off-highway applications. Valvoline’s formula is engineered to resist oxidation, deposits, corrosion, and wear better than industry standards. They are formulated for faster and safer cold starts and have enhanced thermal properties for hot weather operations. Plus, extended drain intervals with Valvoline Premium Blue full synthetic reduce oil changes. According to the company, Valvoline Premium Blue isthe only diesel engine oil recommended and endorsed by engine maker Cummins. 

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