Maintaining the 2008 GMC Acadia with its robust 3.6L V6 engine requires a disciplined approach to fluid changes. This mid-size crossover SUV was designed for family utility, capable of handling towing and hauling, but its longevity depends heavily on the quality of lubricants used. The engine’s 3.6L displacement generates significant heat and stress, making synthetic formulations essential for preventing wear, reducing sludge, and extending service intervals. By selecting the correct viscosity and high-performance additives, owners can ensure the vehicle remains reliable through high mileage and varied driving conditions. The right choice is AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil or AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil.
Recommended AMSOIL Products
To optimize performance and protection for your 2008 Acadia, the following AMSOIL fluids and filters provide superior coverage compared to conventional options.
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Offers unsurpassed engine protection against horsepower loss and wear for up to 25,000 miles, ideal for severe driving conditions and extreme temperatures.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Provides extended service intervals of up to 20,000 miles with enhanced cleaning power to keep the engine running smoothly and prevent low-speed pre-ignition.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – A cost-effective synthetic option that fights sludge and deposits while meeting OEM requirements for turbocharger protection.
- AMSOIL Oil Filter EA15K50-EA – Engineered with superior media to provide 99% filtration efficiency at 20 microns, offering greater capacity for contaminants and lower restriction to keep engine parts lubricated.
- WIX Oil Filter 57060-EA – A premium aftermarket option that offers improved filtration media and performance over original equipment manufacturer branded filters.
The engine oil capacity for the 3.6L V6 is 5.5 quarts when the filter is replaced. Always ensure the oil level is checked after refill to maintain proper lubrication. The torque specification for the oil drain plug is 18 ft/lbs, a detail often overlooked but crucial for preventing leaks or stripped threads during routine maintenance.
Transmission and Drivetrain Fluids
The 2008 Acadia is equipped with a 6T75 six-speed automatic transmission, a unit that benefits significantly from synthetic fluid. Using a high-quality automatic transmission fluid helps protect against wear, sludge, and the elevated temperatures associated with towing or stop-and-go traffic. For this transmission, the total fill capacity is 9.5 quarts, while the initial fill capacity sits at 4.2 quarts, though actual capacity typically ranges between 4.0 and 6.0 liters depending on the drain and fill method.
AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is designed to withstand the rigors of heavy towing and challenging terrain. It remains fluid in sub-zero temperatures, ensuring smooth shifts even in cold climates, and provides reserve protection during heavy use or abuse. For those seeking a fuel-efficient option that matches original equipment specifications, AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers robust protection against wear while maximizing fuel economy.
For the transfer case and rear differential, which utilize gear lubricants, the 2008 Acadia requires AMSOIL SEVERE GEAR 75W-90 100% Synthetic Gear Lube. This synthetic lubricant is particularly effective for limited-slip applications. The transfer case (GETRAG 790) has a capacity of 2.1 pints, and the rear differential (SL136) also holds 2.1 pints. The drain and fill plug torque specifications are 29 ft/lbs. AMSOIL SEVERE GEAR helps control thermal runaway, reduces operating temperatures, and protects against rust and corrosion, extending the life of seals and equipment.
Cooling System and Braking Fluids
Proper cooling system maintenance is vital for preventing overheating, which can be detrimental to the engine and head gasket over time. The 2008 Acadia’s cooling system holds approximately 12.3 quarts of fluid. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a unique poly-organic acid (OAT) formulation that provides protection for up to 150,000 miles or 5 years. It is compatible with all other antifreeze and coolant colors and is free from phosphates, nitrates, and silicates, ensuring compatibility with all cooling system metals and hoses.
For those preferring a concentrated option, AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers superior protection against metallic corrosion and erosion. This product requires mixing with distilled water but delivers extended service intervals up to 150,000 miles for passenger cars and light trucks. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is recommended for the braking system, providing excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range.
Additional Fluids and Protection
Beyond the primary mechanical components, the 2008 Acadia also utilizes power steering fluid. The recommended type is PS004, for which AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is an ideal upgrade. This fluid reduces friction, helps seals remain soft to prevent leaks, and resists heat for long fluid life. It is formulated for quiet operation and offers excellent high-temperature and low-temperature performance.
To maintain peak engine performance and fuel economy, adding a fuel treatment is highly recommended. AMSOIL P.i. Performance Improver restores up to 14% horsepower and cleans GDI fuel injectors to 100% flow rate, helping prevent carbon buildup and knock. For seasonal storage, AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months, protecting against varnish and gum buildup. AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor lubricates the fuel system and upper cylinders, compatible with capless fuel systems.
General maintenance and care products are also available, including AMSOIL Engine Fogging Oil for long-term engine storage, AMSOIL Synthetic Multi-Purpose Grease for chassis components, and AMSOIL Heavy-Duty Metal Protector for undercarriage rust prevention. For cleaning, options include AMSOIL Engine Degreaser, AMSOIL Brake and Parts Cleaner, and various car care items like AMSOIL Miracle Wash Waterless Wash and Wax Spray and AMSOIL Exterior Ceramic Spray.
Vehicle Background
The 2008 GMC Acadia represents a significant entry into the mid-size crossover segment for General Motors. As a flagship sibling to the Chevrolet Traverse, the Acadia was designed to offer the utility of a traditional SUV with the ride quality and handling of a car. The vehicle is built on the Theta II platform, which provided a solid foundation for its spacious three-row seating arrangement. It is particularly notable for its introduction of the 3.6L V6 engine, which replaced smaller four-cylinder options in other GM crossovers of the era, delivering a robust blend of power and efficiency that appealed to families needing to haul cargo or passengers over long distances.
Owners of the 2008 Acadia typically value its versatility and smooth ride. The vehicle was positioned as a premium option in its class, often featuring higher trim levels with luxury amenities that rivaled larger trucks. Its unibody construction contributed to a lower center of gravity compared to body-on-frame SUVs, making it more comfortable for daily commuting and highway travel while retaining enough capability for light towing. The 3.6L engine, known for its durability and refined power delivery, became a staple in GM’s lineup, powering numerous vehicles and earning a reputation for reliability when properly maintained. The Acadia’s design focused on maximizing interior space, offering a cabin that felt airy and accommodating, which made it a popular choice for growing families. While it shares its platform with several other GM models, the Acadia carved out a distinct identity with its refined styling and emphasis on comfort, distinguishing itself as a sophisticated family hauler in a market increasingly dominated by crossovers. Over the years, it has developed a reputation as a dependable daily driver, capable of handling diverse driving conditions with ease.