The 2021 Toyota 4-RUNNER equipped with the 4.0L V6 engine is a legendary SUV known for its durability and off-road capability. Under the hood lies the robust 1GR-FE engine, a powerplant designed for years of reliable service. However, like any complex mechanical system, its longevity depends heavily on the quality of fluids circulating through it. Using the correct lubricants ensures that engine components stay clean, moving parts are adequately protected against wear, and heat is effectively managed even under heavy loads or extreme temperatures.
Recommended AMSOIL Products
- AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil – Provides unsurpassed engine protection with up to 25,000 miles of guaranteed service and significant resistance to horsepower loss and wear.
- AMSOIL Extended-Life 0W-20 100% Synthetic Motor Oil – Offers extended oil change intervals with up to 20,000 miles of protection and enhanced cleaning power to keep the engine running smoothly.
- AMSOIL OE 0W-20 100% Synthetic Motor Oil – An economical option formulated to fight sludge and deposits while delivering protection that meets or exceeds standard requirements.
- AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil – Specifically designed for vehicles over 75,000 miles, featuring boosted detergents to reduce sludge and seal conditioners to minimize oil consumption.
- AMSOIL Oil Filter – Delivers 99% filtration efficiency at 20 microns with greater capacity for contaminants than many competitors, offering extended service life.
- WIX Oil Filter – A premium aftermarket option featuring high-quality media that offers improvements over original equipment manufacturer-branded filters.
- WIX Air Filter – Ensures clean airflow to the engine with premium media for improved filtration performance.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A ready-to-use 50/50 pre-mix that protects cooling system metals, gaskets, and hoses for up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated formula offering superior corrosion protection and up to 150,000 miles of service in passenger cars and light trucks.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands heavy towing, high temperatures, and challenging terrain while maintaining fluidity in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A cost-effective synthetic fluid that protects against wear and ensures smooth shifting performance.
- AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube – Advanced protection for front and rear differentials that controls thermal runaway and protects against rust and corrosion.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides excellent responsiveness and a stable viscosity over a wide temperature range for consistent braking performance.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Suitable for power steering applications, this fluid offers reserve protection during heavy use and extreme conditions.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Guards against leaks and promotes smooth, shudder-free shifts in power steering and transmission systems.
Engine Oil and Filtration Requirements
For the 2021 Toyota 4-RUNNER’s 4.0L V6 engine (Code 1GR-FE), the manufacturer specifies a viscosity grade of 0W-20. This grade is critical for optimal fuel economy and ensuring quick lubrication during cold starts. The engine oil capacity, including the filter replacement, is 6.6 quarts. When performing an oil change, it is essential to torque the oil drain plug to 30 ft/lbs and always install a new washer on the drain bolt to prevent leaks.
Selecting the right oil depends on your driving patterns. If your vehicle has accumulated significant mileage, the AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil is an excellent choice. Its unique chemistry addresses issues common in older engines, such as increased oil consumption and sludge buildup. For drivers seeking maximum protection and extended drain intervals up to 25,000 miles, the AMSOIL Signature Series 0W-20 is the premium option. It offers 75% more engine protection against horsepower loss compared to industry standards.
The AMSOIL Oil Filter plays a vital role in this system. Standard filters often become a bottleneck, forcing oil to bypass the media once the pressure builds up. It is designed to allow lower restriction, ensuring oil flows freely to lubricate critical engine parts even under high pressure. It also possesses a larger capacity for trapping small, wear-causing contaminants, which helps reduce engine wear over time. For those preferring a premium aftermarket brand, the WIX Oil Filter provides a reliable alternative with premium media that outperforms many OEM filters.
Transmission and Differential Fluids
The automatic transmission in the 4-RUNNER, identified as the A750E or A750F series, requires a fluid capable of withstanding the rigors of both highway cruising and off-road towing. The total fill capacity for the 5-speed transmission is 11.3 quarts, though an initial fill is only 1.8 quarts. Using a high-quality synthetic fluid like the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid ensures the transmission remains fluid in sub-zero temperatures while providing reserve protection during heavy use. The AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers a budget-friendly synthetic alternative that protects against wear and ensures reliable performance.
Proper lubrication of the drive train is equally important. The 4-RUNNER utilizes GL-5 rated gear lubricants for both the front (partial or full-time) and rear differentials, requiring a 75W-85 viscosity. Whether you have a standard or limited-slip differential, the AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube is the recommended choice. It contains friction modifiers specifically for limited-slip applications and helps control thermal runaway, a common issue in heavy towing scenarios. It effectively reduces operating temperatures and extends the life of seals and equipment.
Coolant and Brake Fluid Specifications
Keeping the engine temperature stable is crucial for the longevity of the 1GR-FE engine. The cooling system capacity is approximately 11.1 quarts. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a phosphate, nitrate, and silicate-free formulation that exceeds OEM requirements. It is designed to protect all cooling system metals, gaskets, and hoses for up to 150,000 miles or five years. For those who prefer a concentrated formula, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers exceptional performance in both extreme cold and high-heat environments.
Braking safety should never be compromised. The 2021 4-RUNNER uses hydraulic brake fluid that meets DOT 3 specifications. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is an excellent upgrade, offering a higher boiling point and stable viscosity that ensures consistent pedal feel and responsive ABS and traction control, even after repeated heavy braking.
Additional Maintenance and Care Products
To maintain peak performance, the fuel system also benefits from attention. The power steering system in this vehicle requires a fluid compatible with DEXRON-III specifications. The AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid can be used here to ensure smooth operation. Furthermore, adding a fuel system cleaner like the AMSOIL P.i. Performance Improver can help restore fuel injectors to 100% flow rate and improve fuel economy.
About the Vehicle
The 2021 Toyota 4-RUNNER represents the fifth generation of this iconic SUV, continuing a lineage that has defined the segment of body-on-frame mid-size SUVs for decades. Powered by the 4.0L V6 engine known as the 1GR-FE, this model produces approximately 270 horsepower and 278 lb-ft of torque. This naturally aspirated powerplant is celebrated not just for its output, but for its legendary reliability and ability to handle severe duty without the complexities associated with turbocharged or smaller displacement engines. It is mated to either a five-speed or six-speed automatic transmission, depending on the specific trim and year, both designed to handle the weight of the vehicle and the demands of off-road trails.
Known for its rugged construction and solid axle rear suspension, the 4-RUNNER is a favorite among outdoor enthusiasts who demand a vehicle that can transition from daily commuting to rock crawling with ease. It sits in a unique market position, bridging the gap between traditional truck-based SUVs and unibody crossovers. Owners appreciate its high ground clearance, available four-wheel-drive systems, and the sheer durability of its chassis. The vehicle’s reputation is built on the ability to keep driving even when conditions are less than ideal, making it a staple for families living in rural areas or those who frequently enjoy overlanding.
Despite its robust design, owners of the 4-RUNNER may encounter specific issues that proper lubrication can mitigate. One common concern with the 1GR-FE engine over high mileage is oil consumption. The engine’s design can sometimes lead to increased oil usage as it ages, a problem that is best managed with high-mileage synthetic oils that contain seal conditioners to maintain gasket integrity and reduce burn-off. Another potential area of wear is the transmission, which can develop shuddering or slipping if the fluid degrades under heavy loads; using a premium synthetic transmission fluid helps maintain fluidity and protects against the wear that causes these shifting issues. Furthermore, the differential gears can suffer from wear or overheating during prolonged off-road use or towing, which is why switching to a heavy-duty synthetic gear lube with thermal stability is highly beneficial. Finally, the cooling system, essential for a vehicle of this size and weight, can be prone to corrosion or seal leaks over time; using a high-quality antifreeze with superior corrosion inhibitors prevents these leaks and ensures the engine stays within its optimal temperature range.
Ultimately, the 2021 4-RUNNER is a vehicle built for a long life, and providing it with the best possible lubricants ensures that this legacy continues. By adhering to the recommended fluid specifications and utilizing advanced synthetic formulas, owners can maximize the vehicle’s performance, efficiency, and durability for years to come.