Proper lubrication for the 2018 Q50 begins with selecting the correct oil viscosity. Infiniti specifies a 0W-20 grade for this turbocharged engine to ensure fast oil flow during cold starts and optimal film strength at operating temperature. The engine oil capacity is 5.7 quarts when including a filter replacement. It is important to note that this capacity assumes the vehicle has the original 25-inch dipstick. If the vehicle has been serviced previously with a replacement dipstick measuring 24.5 inches, an additional 0.5 quarts may be required to reach the correct level. Always check the oil level after refilling to ensure accuracy.
While 0W-20 is the required specification, vehicle owners have a range of premium AMSOIL Signature Series Motor Oil that meet or exceed factory standards. The AMSOIL OE 0W-20 100% Synthetic Motor Oil offers a formulation specifically designed to fight sludge and deposits, providing a cost-effective route to synthetic protection. For drivers looking to extend their oil change intervals without compromising protection, the OE variant can also be a robust choice. Those who have pushed their vehicles beyond 75,000 miles will find value in the AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil. This formulation features a boosted detergent package and enhanced anti-wear additives that help reduce sludge and clean the engine internally, supporting the longevity of high-mileage turbos.
Filter selection is equally critical for a twin-turbo engine. The AMSOIL Oil Filter is rated for extended service life, offering filtration efficiency of 99 percent at 20 microns. This high-efficiency media allows the engine to run cleaner for longer periods, which is particularly beneficial for the tight tolerances found in the VR30DDTT engine. If you prefer an aftermarket alternative, the WIX Oil Filter provides premium media that improves upon original equipment manufacturer filters.
The cooling system on the Q50 requires a specific volume of fluid. With a capacity of 9.3 quarts, ensuring the coolant is top-tier is vital for preventing overheating in the turbocharged engine. The AMSOIL Propylene Glycol Antifreeze and Engine Coolant is a concentrated option that allows for precise mixing ratios. It offers protection for up to 150,000 miles and greatly surpasses standards for metallic corrosion. Alternatively, the AMSOIL Passenger Car & Light Truck Antifreeze & Coolant comes pre-mixed as a 50/50 solution, ready to fill the system with a phosphate-, nitrate-, and silicate-free formula that is safe for all cooling system metals and gaskets.
Transmission health is paramount for the Q50, which utilizes a 7-speed RE7R01A automatic transmission. A total fill requires 10.6 quarts of fluid. The AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid remains fluid in extreme cold while providing reserve protection during heavy use and towing. For those seeking an OE-matching fluid, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid ensures smooth, shudder-free shifts and guards against leaks. Additionally, the AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid resists harmful sludge and promotes efficient operation.
For the differential and transfer case, AMSOIL offers specialized gear lubes. The front differential requires 1.4 pints, while the rear requires 2.2 pints of a synthetic lubricant. The AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube is highly recommended for its advanced protection against wear and its ability to control thermal runaway in limited-slip applications. It also contains friction modifiers to ensure smooth engagement. For extreme conditions, the AMSOIL SEVERE GEAR® 80W-90 or the AMSOIL SEVERE GEAR® 75W-110 provide robust protection. For those prioritizing maximum service intervals, the AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube is engineered for a 500,000-mile service life, offering improved seal life and corrosion protection.
Maintaining the braking system is a safety priority. The Q50 requires a DOT 3 compatible fluid. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid ensures excellent ABS and traction-control responsiveness. Its stable viscosity over a wide temperature range helps maintain consistent brake pedal feel. For fuel system maintenance, the AMSOIL P.i.® Performance Improver Gasoline Additive is highly effective for direct injection (GDI) engines, restoring fuel injectors to 100% flow rate and helping prevent carbon buildup.
Vehicle Background
The 2018 Infiniti Q50 is a sophisticated luxury sports sedan that succeeded the G37 and G35 models in the Infiniti lineup. It is built on the Nissan D platform, sharing its underlying architecture with the Nissan Maxima, but Infiniti has tuned it to deliver a distinctly more sport-oriented driving experience. The vehicle is known for its sharp styling, featuring a bold double-arch grille that is a signature design element of the brand’s “Double Arch” philosophy. The cabin is generally regarded as a driver-centric environment, offering high-quality materials, supportive front seats, and a focus on minimizing driver fatigue during long trips.
Under the hood, the 3.0L V6 twin-turbocharged engine is the heart of the Q50’s performance credentials. This direct-injected powerplant, code-named VR30DDTT, produces substantial horsepower and torque figures, allowing for quick acceleration that rivals V8 competitors. The engine’s dual-twin-scroll turbochargers are designed to reduce lag, providing power across a wide rev range. The Q50 is also notable for its advanced suspension technologies, including the Sport Hybrid model which incorporates an electric torque vectoring system to enhance handling dynamics and cornering stability. This makes the vehicle a favorite among enthusiasts who appreciate both straight-line speed and agile cornering capabilities.
Despite its robust engineering, the 2018 Q50 is not without challenges that regular maintenance can mitigate. One common issue reported by owners involves carbon buildup on the intake valves, a typical occurrence with direct injection engines where fuel does not wash over the valves. Using fuel additives like AMSOIL P.i. can help mitigate this over time. Another area of concern is the potential for coolant leaks, particularly around the thermostat housing or water pump, which can be exacerbated by standard coolants failing to protect against erosion over time. Switching to a high-quality antifreeze like AMSOIL can improve corrosion resistance. Additionally, some owners have noted issues with the rear differential or transfer case in AWD models experiencing shudder or noise, often linked to the degradation of the gear lubricant under thermal stress; using a premium synthetic gear lube can restore smooth operation. Finally, the high-stress nature of the turbocharger system can lead to sludge formation if oil changes are delayed; the superior shear stability of AMSOIL Signature Series synthetic oils ensures the lubricant film remains intact, protecting the turbo bearings from premature wear.
For owners seeking a complete solution, the AMSOIL P.C. Membership offers significant savings on these essential fluids and filters. By utilizing these high-performance lubricants, you ensure that your Infiniti Q50 receives the same level of protection it would in a professional racing environment. This proactive approach not only extends the life of the engine and transmission but also maintains the vehicle’s resale value by keeping the powertrain in peak condition.