The 2008 Volvo S40 equipped with the 2.4-liter, five-cylinder engine (Code 38 B5244S4-1) represents a robust choice for drivers seeking Scandinavian reliability and a smooth driving experience. Proper maintenance is the single most effective way to preserve the longevity and performance of this vehicle. Using incorrect fluids can lead to premature wear, reduced fuel efficiency, and costly repairs. For this specific engine, the manufacturer recommends a SAE 5W-30 viscosity grade. In extreme temperatures, or when towing, 0W-30, 0W-40, or 5W-40 oils are also suitable alternatives. The system requires 6.1 quarts of oil, including the filter change. Selecting a premium synthetic lubricant ensures that the turbocharger is protected and that the engine stays clean even under severe driving conditions.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Offers unsurpassed engine protection against horsepower loss and wear, trusted by professional engine builders for up to 25,000 miles or one year. This oil is formulated to protect turbochargers 72% better than required specifications.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Provides 37% more cleaning power to keep the engine running smoother for longer. It is guaranteed for 20,000 miles between changes, making it an excellent choice for drivers who want extended intervals without sacrificing protection.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – A premium synthetic formulation designed to fight sludge and deposits effectively. It is API licensed and offers protection comparable to or exceeding original equipment manufacturer standards for normal service conditions.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Specifically engineered for vehicles with over 75,000 miles. This formula features boosted detergents and dispersants to reduce sludge by 67% and includes enhanced anti-wear additives to help engines with higher mileage perform better.
- AMSOIL Oil Filter – Provides a filtering efficiency of 99 percent at 20 microns, helping to reduce engine wear by capturing small, wear-causing contaminants. It allows lower restriction to keep parts lubricated and offers a capacity for contaminants greater than many competing filters.
- MANN-FILTERS Oil Filter – A premium alternative that offers improvements over standard OEM-branded filters, featuring premium media for effective filtration and reliable engine protection.
- MANN-FILTERS Air Filters – These filters use premium media that offers improvements over original equipment manufacturer-branded filters, ensuring clean airflow reaches the engine for optimal combustion and efficiency.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid (OAT) formulation that protects cooling system metals, gaskets, and hoses. This ethylene glycol 50/50 pre-mix provides protection up to 150,000 miles or 5 years and is compatible with all other antifreeze colors.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated formulation requiring mixing with distilled water, offering extended protection up to 150,000 miles or 5 years in passenger cars. It greatly surpasses standards for metallic corrosion and erosion protection.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Withstands the rigors of heavy towing, elevated temperatures, and challenging terrain. It remains fluid in sub-zero temperatures, providing reserve protection during heavy use and abuse for automatic transmissions.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Excellent for resisting harmful sludge and providing outstanding cold-weather performance. This fluid guards against leaks and promotes smooth, shudder-free shifts in automatic transmissions.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with stable viscosity over a wide temperature range, ensuring safe and consistent braking performance in all conditions.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Helps seals remain soft to prevent leaks while reducing friction. It resists heat for long fluid life and provides strong anti-wear protection with excellent high-temperature performance for quiet operation.
Engine Oil and Filtration Standards
The heart of the 2008 Volvo S40 is the naturally aspirated, 2.4-liter inline-five engine known as the B5244S4. While it is not a high-revving race engine, it is renowned for its durability and smooth power delivery. To keep this engine running at its peak, adhering to the correct oil capacity and viscosity is crucial. The system holds 6.1 quarts of oil when the filter is replaced. The recommended viscosity is 5W-30 for standard driving conditions. However, owners operating in extreme temperatures or towing trailers may benefit from 0W-30, 0W-40, or 5W-40 synthetic oils. The drain plug torque specification is 28 ft/lbs, and it is essential to check the oil level immediately after the refill to ensure proper lubrication levels are achieved.
Selecting the right filter is equally important. The standard AMSOIL Oil Filter is designed specifically to match the flow requirements of this engine while maximizing contaminant removal. It features a high-capacity media design that captures wear-causing particles, preventing them from circulating through the engine’s vital components. For those looking for an alternative to the AMSOIL branded filter, the MANN-FILTERS Oil Filter is also a compatible and premium choice, offering media quality that rivals original equipment manufacturer standards. A high-performance air filter is also recommended to ensure the engine breathes efficiently; the MANN-FILTERS Air Filter provides this protection, helping to maintain fuel economy and engine responsiveness.
Transmission and Fluid Systems
The 2008 Volvo S40 is typically equipped with an AW55-51 automatic transmission. Proper maintenance of this transmission is key to preventing shuddering and ensuring smooth gear changes. The system requires a specific fluid to meet Volvo’s JWS3309 specification. A total fill capacity of 8.2 quarts is required for a complete transmission service. Using a high-quality synthetic automatic transmission fluid helps protect against wear, sludge buildup, and temperature-related issues that can shorten transmission life.
The AMSOIL Signature Series Multi-Vehicle Automatic Transmission Fluid is an ideal choice for this application. Its synthetic formulation allows it to withstand the heat and stress of stop-and-go traffic or aggressive driving while maintaining fluidity in cold weather. It helps reduce the occurrence of shudder and provides a reserve of protection during heavy use. For drivers who prefer a cost-effective option without sacrificing performance, the AMSOIL OE Multi-Vehicle Automatic Transmission Fluid is also fully compatible. It offers excellent cold-weather performance and helps prevent leaks, promoting shudder-free shifts throughout the life of the transmission.
Cooling, Braking, and Steering
The cooling system for this Volvo requires specific attention to the type of antifreeze used. The capacity for the cooling system varies based on the specific configuration, with capacities listed as 10 quarts with MTXL10 or 10.6 quarts with ATXL10. AMSOIL offers two excellent options for this vehicle. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a 50/50 pre-mixed ethylene glycol solution that protects against freezing and boiling while safeguarding gaskets and hoses. It is phosphate, nitrite, and silicate-free, ensuring compatibility with various metals and other AMSOIL Propylene Glycol Antifreeze and Engine Coolant. For those who prefer a concentrated fluid, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant provides superior corrosion protection and can be mixed to achieve the desired freeze point.
Braking performance and steering response are critical safety factors. The S40 utilizes a hydraulic brake system that requires DOT 4 fluid. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is formulated to provide excellent responsiveness for ABS and traction-control systems. Its stable viscosity ensures consistent pedal feel regardless of temperature fluctuations. Similarly, the power steering system, which often utilizes Pentosin-compatible fluids, benefits greatly from the AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid. This fluid reduces friction, helps prevent leaks by keeping seals soft, and resists the high temperatures generated during steering maneuvers, ensuring quiet and reliable operation.
Additional Maintenance and Vehicle Care
Beyond standard fluid changes, protecting the fuel system and cleaning the engine bay are important aspects of owning a Volvo S40. Fuel additives like the AMSOIL P.i. Performance Improver Gasoline Additive can restore up to 14% horsepower and clean fuel injectors, improving fuel economy. For seasonal storage, the AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months, preventing varnish and gum buildup. The AMSOIL Engine Fogging Oil is also an excellent choice to protect internal engine components during long periods of inactivity.
For exterior and interior care, AMSOIL offers a range of detailing products. The AMSOIL Miracle Wash Waterless Wash and Wax Spray allows for a clean and protected finish without the need for water. The AMSOIL Exterior Ceramic Spray provides a durable, water-shedding coating, while the interior detailers help trap odors and provide UV protection. To tackle heavy grime, the AMSOIL Heavy-Duty Degreaser effectively dissolves oil and tar from engine surfaces, and the AMSOIL Brake and Parts Cleaner removes contaminants from brake components to eliminate squeal. These products ensure the vehicle not only runs well but looks its best as well.
About the Vehicle
The 2008 Volvo S40 sits comfortably in a segment defined by understated elegance and safety. Produced as part of the compact sedan lineup, the S40 offered a refined driving experience that set it apart from many of its competitors. The specific 2.4-liter, five-cylinder engine found in this model is a testament to Volvo’s engineering philosophy, delivering a smooth and linear power curve that many drivers find more pleasant than the jerky power delivery of four-cylinder engines of the era. With 165 horsepower, the S40 was never marketed as a sports sedan, but it possessed a robust build quality and a reputation for reliability that kept it on the road for many years.
Volvo introduced the S40 to the North American market to offer a smaller, more affordable alternative to their larger sedan lines, while still maintaining the brand’s core values of safety and durability. The second generation S40, which includes the 2008 model year, featured a redesigned chassis and improved interior materials, making it one of the better-handling compacts of its time. The five-cylinder engine is particularly beloved by enthusiasts for its distinctive exhaust note and the fact that it lacks the vibration often associated with straight-four engines of the same displacement. It is a vehicle that rewards attentive maintenance, and for owners who prioritize longevity and smooth operation, the S40 remains a satisfying choice even two decades after its production.