10 Best Synthetic Engine Oil of August 2025

• Innovative anti-wear additives provide 50% more wear protection than industry standards as tested in the industry Sequence IVA wear test
• Full synthetic formula for exceptional high and low temperature protection
• Extra detergents help fight sludge and deposits
• Superior antioxidants resist motor oil breakdown in extreme conditions

Valvoline

• For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
• Formulated for longer drain intervals
• Helps prevent build up that can cause rust and corrosion
• Reduces friction for less engine wear
• High resistance to viscosity and thermal breakdown
• Helps reduce exhaust emissions

Amazon Basics

• Dramatically reduce engine wear
• Leave critical engine parts 4X smoother* * As tested in the industry Sequence IVA wear test
• Superior wear protection on critical engine parts
• Meets Specifications: API SN Plus, ILSAC GF-5, GM dexos1 Gen 2, Ford WSS-M2C929-A, WSS-M2C946-B1
• Castrol recommends the use of Bosch oil filters

Castrol

• -Dramatically reduce engine wear
• -Leave critical engine parts 4X smoother* * As tested in the industry Sequence IVA wear test
• -Superior wear protection on critical engine parts
• -Unsurpassed level of protection against viscosity breakdown
• -Unique full synthetic technology to fight against harmful sludge build-up
• -High level of fuel economy based on US industry standards
• -API SN; ILSAC GF-5; GM dexos1

Castrol

• For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
• Ideal for engines over 75,000 miles and for longer drain intervals
• Helps prevent build up that can cause rust and corrosion
• Reduces friction for less engine wear
• High resistance to viscosity and thermal breakdown
• Helps reduce exhaust emissions

Amazon Basics

• 100% Synthetic SAE 5W-30
• For Use In All Air Cooled 4-cycle Engines
• 32 Oz. bottle

Briggs & Stratton

• For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
• Excellent overall lubrication and wear protection
• Outperforms our conventional high mileage oils
• Helps protect critical engine parts in higher mileage engines
• Helps reduce the sludge and deposits that conventional oils can leave behind
• Helps prevent leaks

Mobil 1

• 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.

Shell Rotella T

• Full synthetic 0W-20 engine oil made from made from natural gas, not crude, using Pennzoil's patented gas-to-liquid PurePlus Technology
• Pennzoil 0W-20 is a carbon neutral motor oil, achieved through verified Nature Based Carbon Credits that offset the CO2 lifecycle emissions
• Provides better fuel economy—drive on average an extra 550 miles per year (versus a dirty engine)
• Pennzoil Platinum 0W-20 keeps pistons up to 45% cleaner than the toughest industry standard (based on Sequence IIIH results)
• No other leading synthetic oil provides better wear protection from friction (Based on Sequence IVA wear test using SAE 5W-30)
• Formulated to provide faster low-temperature oil flow and protection in extreme heat
• Single 5-quart bottle with ergonomic design for easy handling and pouring
• Helps protect engines from loss of power
• Pennzoil is the first motor oil made from natural gas, not crude — PurePlus Technology converts pure natural gas into high-quality, full-synthetic base oil that's crystal clear and contains fewer impurities than other traditional and synthetic motor oils
• Formulated for modern turbocharged engines—GF-6b, API SP/SP-Resource Conserving and all previous categories

Pennzoil

• Advanced premium full synthetic motor oil to offer strength under extreme pressure
• Titanium strong for maximum engine performance
• Reduces metal-to-metal contact across a range of different driving speeds
• Protects the engine for the entire drain interval even under extreme pressure
• Decreases engine deposit formation to help maximize engine response
• Best full synthetic money can buy
• API SN, ILSAC GF-5, ACEA A1/B1, A5/B5, GM dexos1, Meets Ford WSS-M2C929-A, Ford WSS-M2C946-A, Honda HTO-06, Meets engine test requirements of Chrysler MS-6395
• Castrol EDGE is 3X stronger than Mobil 1 against viscosity breakdown* *Tested in the ASTM D6278 test in the 5W-30 viscosity grade.

Castrol