The 2008 Mitsubishi Endeavor with the 3.8L V6 engine requires specific lubrication to maintain optimal performance and longevity. This powertrain, identified by the 6G75 S engine code, was designed to provide reliable power for a family-friendly SUV, but keeping it running smoothly depends heavily on using the correct viscosity and high-quality synthetic fluids. Owners who stick to the recommended 5W-20 viscosity and switch to premium synthetic blends will see significant benefits in terms of reduced wear, improved fuel economy, and extended drain intervals compared to conventional mineral oils.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-20 100% Synthetic Motor Oil – The top-tier choice offering unsurpassed protection against horsepower loss and wear for up to 25,000 miles or one year.
- AMSOIL Extended-Life 5W-20 100% Synthetic Motor Oil – Provides extended protection for up to 20,000 miles with excellent cleaning power to keep the engine running smoother.
- AMSOIL OE 5W-20 100% Synthetic Motor Oil – A cost-effective 100% synthetic option that fights sludge and deposits, perfect for those seeking OEM-mileage performance.
- AMSOIL 5W-20 100% Synthetic High-Mileage Motor Oil – Specially formulated for engines over 75,000 miles with boosted detergents and anti-wear additives to reduce sludge.
- AMSOIL Oil Filter – Features 99% efficiency at 20 microns and greater capacity to capture contaminants, extending service life and protecting engine parts.
When selecting the right motor oil for your 2008 Endeavor, the 6G75 S engine specifically calls for SAE 5W-20 viscosity across all temperatures. This grade is preferred by Mitsubishi for this engine code and ensures proper flow during cold starts while maintaining adequate thickness at operating temperatures. The engine oil capacity is 4.5 quarts when the filter is included, which is a standard volume for this displacement. After refilling the crankcase, it is crucial to check the oil level to ensure it is correct before running the engine. When draining the oil, the oil drain plug should be torqued to a precise 26-32 ft/lbs to prevent leaks or damage to the threads. Owners looking for the absolute best protection should consider the AMSOIL Signature Series 5W-20 100% Synthetic Motor Oil, which delivers up to 75% more engine protection against horsepower loss and wear compared to standard oils. For those driving vehicles with over 75,000 miles, the AMSOIL 5W-20 100% Synthetic High-Mileage Motor Oil is ideal, as its unique chemistry includes a boosted detergent package that helps clean internal components and reduce sludge accumulation.
Engine Filtration and Air Intake
Clean oil is only half the equation; the filter is the other half of the protection system. The AMSOIL Oil Filter (EA15K13-EA) is engineered to work seamlessly with these synthetic oils. It provides extended service life, meaning it can often handle the long drain intervals associated with AMSOIL synthetic motor oils without becoming a restriction point. The filter media captures small, wear-causing contaminants more effectively than many competing brands. Alternatively, the WIX XP Oil Filter (51356XP-EA) offers premium media improvements over standard OEM-branded filters, providing a robust backup option for those who prefer the WIX brand name. Additionally, ensuring the engine breathes through a clean WIX Air Filter (46873-EA) is vital for combustion efficiency, keeping dust and debris out of the engine to support the longevity of the internal components.
Transmission Fluid Specifications
The automatic transmission in the 2008 Endeavor, which includes the W4A5A-4 and F4A5A-4 models (SL065), requires specific attention to fluid viscosity and formulation. The total fill capacity for the 4-speed automatic transmission varies slightly by configuration, with totals reaching 9.3 quarts for the W4A5A-4 and 8.9 quarts for the F4A5A-4. Using a high-quality synthetic fluid is essential for this transmission to withstand the rigors of heavy towing and elevated temperatures. The AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid remains fluid even in sub-zero temperatures while providing reserve protection during heavy use. It resists the formation of harmful sludge and promotes smooth, shudder-free shifts. For owners who want a premium yet more budget-friendly option, the AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid also delivers excellent performance, guarding against leaks and ensuring reliable operation.
AMSOIL Passenger Car & Light Truck Antifreeze & Coolant and Cooling System
Maintaining the correct AMSOIL Propylene Glycol Antifreeze and Engine Coolant mixture is critical for preventing overheating and corrosion in the Endeavor’s engine cooling system. The fluid capacity varies based on the vehicle’s drivetrain and package. Front-Wheel Drive (FWD) models require 9.5 quarts of coolant. All-Wheel Drive (AWD) models equipped with a tow package generally require 10.1 quarts, while AWD models with a specific other tow package require 9.5 quarts. AMSOIL offers two primary options: the AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a pre-mixed 50/50 ethylene glycol solution that protects metals, gaskets, and hoses, offering up to 150,000 miles or 5 years of protection. For a more concentrated option that allows for custom mixing with distilled water, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant provides superior protection against metallic corrosion and erosion, extending maintenance intervals significantly.
Transfer Case and Differential Lubrication
If your 2008 Mitsubishi Endeavor is equipped with a transfer case or a rear differential, using the correct AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube is vital for smooth power transfer and durability. The transfer case typically holds 1.1 pints and requires a fill plug torque of 22-25 ft/lbs. The rear differential holds 2.3 pints. For these components, AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube products are designed to control thermal runaway and protect against rust and corrosion. The AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube is an excellent all-around choice that includes friction modifiers suitable for limited-slip applications. For those seeking enhanced extreme pressure protection, the AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube or the heavier AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube offer superior performance in severe service conditions, helping to reduce operating temperatures and extending the life of seals and equipment.
Brake and Power Steering Fluids
Safety components like brakes and power steering systems rely on consistent fluid performance. For the hydraulic brake system, which typically uses DOT 3 fluid, the AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is the recommended choice. It offers excellent responsiveness for ABS and traction control systems and maintains a stable viscosity across a wide temperature range, ensuring consistent pedal feel. For the power steering system, which requires fluid meeting the PS016 specification, the AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is ideal. This fluid reduces friction, helps seals remain soft to prevent leaks, and provides strong anti-wear protection, ensuring the steering system operates quietly and smoothly even in high-temperature conditions.
Proper fluid maintenance goes beyond just oil changes. Using fuel additives can also play a role in keeping the vehicle running efficiently. The AMSOIL P.i.® Performance Improver Gasoline Additive helps restore fuel injectors and improve fuel economy, while the AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor lubricates the fuel system and upper cylinders to prevent corrosion. For those planning to store the vehicle or if it sees infrequent use, the AMSOIL Gasoline Stabilizer helps keep fuel fresh for up to 12 months, and the AMSOIL Engine Fogging Oil protects internal components from rust during inactivity. Additionally, general maintenance products like the AMSOIL Synthetic Multi-Purpose Grease offer excellent resistance to thermal degradation for chassis lubrication, and the AMSOIL Heavy-Duty Degreaser is useful for cleaning the engine bay and other parts. Keeping the vehicle clean with products like the AMSOIL Miracle Wash Waterless Wash and Wax Spray or the AMSOIL Exterior Ceramic Spray can also help preserve the paint and appearance, ensuring the Endeavor remains in top condition inside and out.
About the Vehicle
The 2008 Mitsubishi Endeavor represents a distinct chapter in the brand’s history as a versatile family-oriented SUV. Built on the same platform as the Outlander, this model was positioned to offer the utility of a traditional body-on-frame vehicle with the ride comfort and fuel economy of a unibody crossover. Powered by a robust 3.8-liter V6 engine, the Endeavor delivered sufficient horsepower to handle both daily commuting and the occasional load of passengers or luggage. The 6G75 S engine code is associated with a naturally aspirated design that was known for its durability, making it a reliable choice for those who needed a vehicle that could handle varied road conditions without the complexity of a turbocharger.
Owners of the Endeavor often appreciate its generous interior space and practical features, which include a spacious third row for children or extra passengers. The vehicle’s market position was unique, offering a blend of soft-roader capability and highway stability that appealed to families who needed more than a standard sedan but didn’t require the ruggedness of a heavy-duty truck. While it was manufactured for the North American market and assembled with a focus on comfort, the Endeavor also garnered a reputation for being a solid, no-nonsense vehicle that valued functionality over flashiness. This balance of utility and reliability is why many owners continue to maintain these vehicles with care, ensuring they continue to serve as dependable family haulers. Regular fluid changes, as outlined in the lubrication guide, are the best way to preserve this character and keep the Endeavor running smoothly for years to come.