Keeping your 2018 Toyota 4-RUNNER running at peak performance requires more than just following the basic manufacturer schedule. The 4.0L 6-cylinder engine (Engine Code 1GR-FE D) is a robust powerplant designed for hauling, towing, and off-road adventures, but it demands high-quality lubricants to maintain its durability over the long haul. Using the correct synthetic fluids ensures maximum protection against the heat and stress of heavy loads while optimizing fuel economy during daily commutes.
Recommended AMSOIL Products
- AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil – Provides the highest level of protection against horsepower loss and wear, offering up to 25,000 miles of service.
- AMSOIL Extended-Life 0W-20 100% Synthetic Motor Oil – Delivers extended protection for up to 20,000 miles with superior cleaning power to keep the engine running smoother.
- AMSOIL OE 0W-20 100% Synthetic Motor Oil – An excellent choice that fights sludge and deposits with a 100% synthetic formulation for OEM-level protection.
- AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil – Specially formulated for vehicles with over 75,000 miles to reduce sludge and enhance performance.
- AMSOIL Oil Filter – Features 99% filtering efficiency at 20 microns to capture wear-causing contaminants and ensure proper lubrication.
- WIX Oil Filter – Offers premium media that improves upon original equipment manufacturer branded filters for reliable protection.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A pre-mixed ethylene glycol formulation providing up to 150,000 miles of corrosion protection.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option designed for long service intervals in passenger cars and light trucks.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands heavy towing, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Protects against wear and ensures smooth shifting for the A750E and A750F transmissions.
- AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube – Offers advanced protection against wear and thermal runaway for differentials and transfer cases.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Ensures excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range.
Selecting the right viscosity is critical for the 1GR-FE engine, which is designed for 0W-20. This weight provides the best balance of fuel economy and cold-start protection for all seasons. The oil capacity for this engine, including the filter change, is 6.6 quarts. It is important to install a new washer on the drain bolt and torque the plug to 30 ft/lbs to prevent leaks. When you upgrade to AMSOIL synthetic motor oil, you gain superior thermal stability and oxidation resistance compared to conventional oils, which is essential for the 4-RUNNER’s V6 engine during demanding off-road excursions or when towing heavy loads.
Transmission and Drivetrain Protection
The 2018 4-RUNNER comes equipped with an automatic transmission (A750E or A750F) that benefits significantly from a synthetic fluid capable of withstanding the rigors of 4-wheel drive systems. The initial fill capacity is 1.8 quarts, while a total fluid change for the 5-speed transmission requires 11.3 quarts. Using a synthetic automatic transmission fluid like AMSOIL’s Fuel-Efficient series helps protect against sludge buildup and maintains consistent shifting quality even under high-stress conditions. For the front and rear differentials, as well as the transfer case, AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube is the recommended choice. It contains friction modifiers specifically beneficial for limited-slip differentials and controls operating temperatures, extending the life of seals and gears. The front differential with a full-time 4WD system requires 3 pints, while the part-time version requires 3.4 pints. The rear standard differential needs 5.7 pints, and the limited-slip rear variant also requires 5.7 pints.
Cooling and Brake Systems
Effective cooling system maintenance is vital for the longevity of the 4.0L engine. The cooling system capacity is 11.1 quarts. You have the option to choose between AMSOIL Passenger Car & Light Truck Antifreeze & Coolant, a pre-mixed formulation, or the concentrated AMSOIL Propylene Glycol Antifreeze, which allows for custom mixing and offers extended service intervals. Both options provide protection for up to 150,000 miles or 5 years. For the braking system, the 4-RUNNER utilizes hydraulic brake fluid. Switching to AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid improves the responsiveness of anti-lock braking systems and traction control, particularly in extreme heat or cold where conventional fluids may boil or thicken.
Vehicle Background
Why Owners Love the 2018 Toyota 4-RUNNER
The 2018 Toyota 4-RUNNER represents the culmination of decades of refinement in the mid-size SUV market. Based on the rugged body-on-frame architecture shared with the Tacoma pickup truck, the 4-RUNNER is built for those who need versatility without sacrificing off-road capability. The 2018 model year features the legendary 1GR-FE 4.0-liter V6 engine, a naturally aspirated powerhouse known for its reliability and smooth power delivery. This engine produces a healthy amount of torque, making it ideal for towing trailers, carrying gear for outdoor adventures, or simply navigating steep mountain passes with ease. The 4-RUNNER sits on a platform that offers excellent ground clearance and a sophisticated suspension system that can handle both highway cruising and rocky terrain with competence.
Owners of this vehicle often appreciate its blend of practicality and ruggedness. It is a favorite among outdoor enthusiasts, off-roaders, and families who need a safe, spacious vehicle that can also double as a workhorse. The interior is designed with durability in mind, featuring materials that stand up to dirt, mud, and the wear and tear of active lifestyles. The 4-RUNNER’s reputation is built on its “bulletproof” reputation, with many examples still running strong well beyond 200,000 miles when maintained properly. However, like any vehicle with a high mileage or heavy-duty usage profile, it faces specific challenges that proper lubrication can mitigate.
One common issue with the 1GR-FE engine is the potential for oil consumption as the vehicle ages. High-temperature operation and the engine’s design can lead to oil burning in older units. Switching to AMSOIL High-Mileage 0W-20 can help reduce oil consumption and seal leaks due to its unique additive package designed to condition seals and reduce sludge. Another frequent concern is engine sludge buildup, particularly if the vehicle has been subjected to short-trip driving or extreme towing. The superior detergency of AMSOIL Signature Series oil helps keep critical engine components clean, preventing the varnish and carbon deposits that can restrict oil flow and damage turbochargers or other sensitive parts.
Transmission shuddering or delayed shifts are also reported by some owners as the vehicle ages. This can often be attributed to the degradation of factory-fill automatic transmission fluid. Regular fluid changes with a high-quality synthetic fluid like AMSOIL’s Fuel-Efficient series can restore smooth shifting and protect the transmission’s clutches and bands from premature wear. Finally, the 4-RUNNER’s 4WD system, specifically the transfer case and differentials, can suffer from wear if the gear lubricant breaks down under heavy loads. The extreme pressure additives in AMSOIL SEVERE GEAR help prevent this, ensuring that the 4-wheel-drive system engages smoothly and reliably, regardless of the terrain. By addressing these common wear points with premium lubricants, owners can significantly extend the service life of their 4-RUNNER and maintain its legendary performance on the road and off.