The correct oil for an Infiniti Q50 depends on the engine, model year and drivetrain. The Q50 was offered with several powertrains, including the naturally aspirated 3.7-liter V6, a hybrid system, a 2.0-liter turbo engine and the 3.0-liter twin-turbo VR30DDTT. Using one oil recommendation or one capacity for every Q50 can result in an incorrect service.
Always confirm the owner’s manual for the exact vehicle. Capacities are approximate because drain time, oil temperature and the amount remaining in the engine can change the refill quantity. Infiniti instructs owners to use the dipstick to establish the final level rather than pouring in the published capacity and assuming it is correct.
2018 Q50 3.0t Oil Specification
For the 2018 Q50 with the VR30DDTT engine, Infiniti recommends Genuine Nissan Motor Oil 0W-20 SN or an equivalent oil that meets the same grade and viscosity requirements. Modern oil standards have advanced since the manual was printed, so a current oil meeting the applicable newer API specification and the required viscosity may be appropriate when it is backward compatible. Check the label and the current Infiniti recommendation.
The twin-turbo engine depends on clean oil for bearings, timing components and turbocharger lubrication. Choose a quality filter with the correct bypass specification and fitment rather than selecting a filter only because the threads appear to match.
2018 Q50 3.0t Oil Capacity
Infiniti’s 2018 manual lists different capacities for rear-wheel-drive and all-wheel-drive VR30DDTT models. With an oil-filter change, the approximate refill capacity is 5-1/8 U.S. quarts for the two-wheel-drive model and 5-3/4 U.S. quarts for the AWD model. Without a filter change, the listed amounts are slightly lower.
These figures are a starting point, not a target that must be added regardless of the dipstick. Add most of the expected amount, start the engine, check for leaks, shut it off and wait more than 15 minutes as directed in the manual before making the final adjustment. Overfilling can be harmful.
2018 Q50 2.0t Oil Specification and Capacity
The 2.0-liter turbo gasoline engine uses a different oil requirement. The 2018 manual specifies an oil meeting Mercedes-Benz specification MB229.5 with SAE 0W-30 viscosity. It also lists 0W-40, 5W-30 and 5W-40 oils meeting MB229.5 as alternatives.
With a filter change, the approximate capacity is 6-5/8 U.S. quarts for the two-wheel-drive version and 7 U.S. quarts for the AWD version. Do not apply these 2.0t numbers to a 3.0t or 3.7-liter engine.
Earlier 3.7-Liter and Hybrid Q50 Models
Early Q50s with the VQ37VHR engine and hybrid models have their own specifications and capacities. Because the hybrid adds different packaging and the manuals vary by model year, verify the exact manual before service. Many internet charts combine G37, Q50 and hybrid information without explaining the differences.
The safest approach is to identify the engine from the VIN and under-hood label, locate the correct manual and record the specification in the maintenance log. Do not rely only on the recommendation printed by a quick-lube computer system.
Choosing the Oil Filter
Use a genuine Infiniti or Nissan filter or a high-quality equivalent that is specifically cataloged for the engine. The filter must have the correct gasket size, thread, internal construction and bypass-valve specification. Counterfeit filters and low-quality copies can look convincing, so purchase from a reputable source.
During installation, make sure the old filter gasket did not remain on the mounting surface. A double gasket can cause a sudden leak after startup. Lightly coat the new gasket with clean oil and tighten according to the filter and vehicle instructions.
Oil-Change Procedure and Safety
Park on a level surface, apply the parking brake and use proper lifting points, a suitable jack and rated jack stands when the vehicle must be raised. Never work under a vehicle supported only by a jack. Hot engine oil can cause burns, so allow enough time to work safely while still achieving a complete drain.
Use a new drain-plug washer where specified. The 2018 manual lists a VR30 drain-plug torque range of 22 to 29 ft-lb and a filter torque range of 11 to 15 ft-lb, although many spin-on filters are also described by gasket contact plus a specified turn. Follow the instructions for the exact filter and engine.
Checking the Final Oil Level
After filling, start the engine and inspect the drain plug and filter for leaks. Shut the engine off and wait the period specified in the manual before checking the dipstick. Remove the dipstick, wipe it clean, reinstall it fully and read it again.
The level should be within the marked range, not necessarily exactly at the top. Add oil in small amounts and recheck. If the level rises between services, smells strongly of fuel or becomes milky, schedule diagnosis rather than simply changing the oil again.
How Often Should Q50 Oil Be Changed?
Later VR30 Q50 models use an oil-control system that calculates the interval according to driving conditions. Severe use can shorten the interval. Frequent short trips, prolonged idling, heavy traffic, extreme temperatures and repeated high-load driving can all be harder on the oil.
Follow the vehicle’s indicator and official schedule, and change the oil promptly when notified. Modified or track-used vehicles may require a more conservative plan developed with a qualified technician or tuner. Extremely short intervals are not a substitute for using the correct oil, maintaining the proper level and correcting fuel or cooling problems.
Common Oil-Change Mistakes
The most common mistakes are using the wrong capacity, mixing specifications without checking compatibility, over-tightening the drain plug, reusing a damaged washer, leaving the old filter gasket in place and failing to verify the level after the engine has circulated the oil.
Keep the receipt and write down the oil brand, viscosity, specification, filter part number, date and mileage. Accurate records are valuable for warranty questions, future diagnosis and resale.
Primary references checked: INFINITI manuals and guides | INFINITI recall lookup | NHTSA recalls and service documents