Maintaining the 2016 Ford FLEX with its 3.5L V-6 engine requires the correct fluids to ensure longevity, performance, and efficiency. This crossover utility vehicle, often driven in a variety of conditions from city commutes to family hauling, places specific demands on its lubrication systems. Using the wrong viscosity or a poor-quality filter can lead to increased wear, reduced fuel economy, and premature engine damage. Proper maintenance ensures the valve train, crankshaft, and bearings receive adequate protection, especially during cold starts or high-load situations like towing. By selecting the right AMSOIL Signature Series 5W-20 100% Synthetic Motor Oil, owners can extend service intervals while keeping the engine running smoother and cleaner for miles to come.
Recommended AMSOIL Products
Below are the verified AMSOIL fluid and filter recommendations for the 2016 Ford FLEX 3.5L engine. These products are specifically formulated to meet the demands of this vehicle.
- AMSOIL Signature Series 5W-20 100% Synthetic Motor Oil – Offers superior protection against horsepower loss and wear, suitable for up to 25,000 miles or one year.
- AMSOIL Extended-Life 5W-20 100% Synthetic Motor Oil – Provides 37% more cleaning power to keep the engine running smoother for up to 20,000 miles.
- AMSOIL OE 5W-20 100% Synthetic Motor Oil – A premium option that fights sludge and deposits effectively while meeting OEM specifications.
- AMSOIL 5W-20 100% Synthetic High-Mileage Motor Oil – Ideal for vehicles with over 75,000 miles, featuring enhanced detergents to reduce sludge and protect aging engines.
- AMSOIL Oil Filter – Delivers 99% filtration efficiency at 20 microns and allows lower restriction to keep engine parts properly lubricated.
- WIX XP Oil Filter – Features premium media that offers improvements over original equipment manufacturer-branded filters.
- WIX Oil Filter – A reliable standard option with premium media for effective contamination control.
- WIX Air Filter – Ensures clean airflow to the engine, preventing contaminants from entering internal components.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix formulation that protects cooling system metals, gaskets, and hoses for up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option that greatly surpasses standards for metallic corrosion and erosion protection.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands heavy towing and elevated temperatures while remaining fluid in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Provides reliable protection against wear for the 6F50 and 6F55 automatic transmissions.
- AMSOIL SEVERE GEAR® 75W-140 100% Synthetic Gear Lube – Recommended for the Power Transfer Unit (PTU) to control thermal runaway and reduce operating temperatures.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – An excellent choice for the rear differential to meet Ford specifications and protect limited-slip applications.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – A versatile AMSOIL SEVERE GEAR® Gear Lube offering advanced wear protection and rust control.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Suitable for heavy-duty rear axle applications requiring high-load protection.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Offers excellent ABS responsiveness and a stable viscosity across a wide temperature range.
- AMSOIL P.i.® Performance Improver – Helps restore horsepower and clean GDI fuel injectors for improved fuel economy.
- AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor – Lubricates the fuel system and upper cylinders to reduce friction.
- AMSOIL Synthetic Multi-Purpose Grease – Resists thermal and oxidation degradation for long-term performance in chassis components.
- AMSOIL Heavy-Duty Metal Protector – Provides a long-lasting protective wax-like coating against rust and corrosion.
- AMSOIL MP Metal Protector – Helps protect against rust and corrosion and displaces water from moving parts.
- AMSOIL Silicone Spray – Protects with a dry lubricating film ideal for rubber and plastic surfaces.
- AMSOIL Heavy-Duty Degreaser – Quickly dissolves oil, tar, and grime from engine surfaces.
- AMSOIL Brake and Parts Cleaner – Removes oil, grease, and brake fluid without leaving residue.
- AMSOIL Engine Degreaser – Professional-strength formula that removes the toughest grease and dirt.
- AMSOIL Glass Cleaner – Cuts through grease and grime for a streak-free finish.
- AMSOIL High-Foam Car Shampoo – A hard-on-dirt, gentle-on-coatings formula for vehicle washing.
- AMSOIL Miracle Wash Waterless Wash and Wax Spray – Cleans and protects without soap or water.
- AMSOIL Exterior Ceramic Spray – Sheds water rapidly and protects against UV rays.
- AMSOIL Interior Detailer – Light Lemon – Multi-surface cleaner with 90-day UV protection.
- AMSOIL Interior Detailer – Scent Free – Multi-surface cleaner that traps and eliminates odors.
For the engine, the 2016 Ford FLEX requires a 6-quart capacity when including the filter. The correct viscosity is 5W-20 for all temperatures. It is crucial to check the oil level after the refill and ensure the oil drain plug is torqued to 20 ft/lbs. The engine oil change can be performed using any of the four recommended AMSOIL motor oils. The Signature Series offers the longest change intervals, while the High-Mileage version is specifically engineered for vehicles that have passed the 75,000-mile mark. Choosing the right filter is just as important as the oil itself, as it traps microscopic particles that can degrade engine performance over time.
The cooling system for this vehicle holds 13.2 quarts of antifreeze. Using a high-quality AMSOIL Passenger Car & Light Truck Antifreeze & Coolant ensures that the metal components, gaskets, and hoses are fully protected against corrosion and erosion. The Propylene Glycol version is available as a concentrated option for those who prefer to mix their own solution with distilled water. For the transmission, the vehicle utilizes a 6-speed automatic unit, either the 6F50 or 6F55. The total fill capacities vary slightly between the two, with the 6F50 requiring 10.9 quarts and the 6F55 requiring 11.6 quarts. AMSOIL’s synthetic automatic transmission fluids are designed to remain fluid in sub-zero temperatures while withstanding the heat generated during heavy towing or challenging terrain.
Differentiation of the drivetrain lubricants is also necessary. The transfer case, identified as the PTU, requires 1.1 pints of SAE 75W-140 synthetic lubricant to prevent thermal runaway and control operating temperatures. For the rear differential in all-wheel-drive models, 2.4 pints of SAE 80W-90 lubricant is required. AMSOIL offers multiple gear lube viscosities to suit different driving conditions and limited-slip requirements, ensuring long oil, seal, and equipment life. Finally, the brake system should be serviced with AMSOIL DOT 3 and DOT 4 Synthetic Brake Fluid, which meets the specific requirements for this Ford model and ensures reliable stopping power in various weather conditions.
Why Proper Lubrication Matters for This Vehicle
The 2016 Ford FLEX is a versatile crossover known for its roomy interior and smooth ride, but it relies heavily on its powertrain to maintain that performance. The 3.5L V-6 engine is a sophisticated piece of machinery that benefits significantly from the precision offered by synthetic lubricants. Unlike conventional oils, AMSOIL synthetic motor oils provide a more stable film strength, which reduces friction and helps protect critical engine components during high-load situations. This is particularly relevant for owners who utilize their FLEX for towing, long-distance commuting, or driving in extreme temperatures. The extended service intervals allowed by these premium oils not only save time and money but also reduce the environmental impact of oil changes. Regularly refreshing the transmission fluid and gear lubricants ensures that the all-wheel-drive system shifts smoothly and operates without excess heat, preventing costly repairs down the road.
In addition to mechanical protection, proper fluids play a vital role in fuel economy. The fuel-efficient formulations of AMSOIL transmission fluids are designed to minimize drag within the transmission, allowing the engine to operate more efficiently. Similarly, using a high-quality AMSOIL antifreeze ensures that the engine reaches operating temperature quickly in cold weather and stays within safe limits during hot weather, preventing overheating and potential engine damage. The synthetic brake fluid has a higher boiling point than standard fluids, which prevents brake fade during repeated or hard stops. By adhering to the recommended fluid schedules and using the specified AMSOIL products, owners can maximize the lifespan and reliability of their vehicle.
About the Vehicle
Produced by Ford Motor Company, the 2016 Ford FLEX represents a unique segment in the automotive market as a mid-size crossover utility vehicle. Unlike the more common SUVs of the era, the FLEX featured a distinctive design with a longer roofline and a more sedan-like profile, offering a spacious interior that could comfortably seat up to seven passengers. It was built on the Ford D4 platform, a unibody construction that provided a blend of car-like handling and utility. The 2016 model year continued to offer the robust 3.5L V-6 engine, which delivered strong acceleration and towing capabilities suitable for families and active lifestyles. This engine was known for its smooth power delivery and was often paired with Ford’s SelectShift automatic transmission, allowing drivers to manually shift gears when desired.
The FLEX was marketed as a practical family hauler, combining the cargo space of a wagon with the ground clearance of an SUV. Its reputation for comfort and versatility made it a popular choice among consumers who needed a capable vehicle without the bulk of a traditional truck-based SUV. The all-wheel-drive system, available on most trims, provided enhanced traction in adverse weather conditions, making it a reliable choice for regions with snow or rain. Over its production run, the FLEX garnered a loyal following for its unique styling and family-friendly features. While the model line was eventually discontinued, the 2016 FLEX remains a solid option for drivers seeking a spacious, comfortable, and capable crossover vehicle. Proper maintenance of its fluid systems is essential to keeping this unique vehicle running smoothly for years to come.