Infiniti Q45 2002-2006 Fuel System Specifications

The 2002-2006 Infiniti Q45 requires premium unleaded gasoline with an octane rating of 91 or higher. Using lower-octane fuel may result in reduced performance, knocking, or engine damage. The vehicle is equipped with a 4.5L V8 engine designed for optimal performance with high-octane fuel. Always refer to the owner's manual for specific fuel requirements and compatibility.

The fuel system in the 2002-2006 Infiniti Q45 requires regular maintenance, including fuel filter replacement every 30,000 miles and periodic inspection of fuel injectors and fuel lines. Use high-quality fuel additives to clean injectors and prevent carbon buildup. Check for fuel leaks and ensure the fuel cap is tightly sealed to maintain system efficiency and avoid emissions issues.

To replace the fuel filter, first, relieve fuel system pressure by disconnecting the fuel pump fuse and running the engine until it stalls. Locate the fuel filter near the fuel tank. Disconnect the fuel lines and remove the filter. Install the new filter, ensuring proper orientation, and reconnect the fuel lines. Restore fuel system pressure and check for leaks before starting the engine.

Poor fuel economy in the Infiniti Q45 may result from clogged fuel injectors, a dirty air filter, or improper tire pressure. Check and replace the air filter, ensure tires are inflated to the recommended pressure, and use a fuel injector cleaner. If issues persist, inspect the oxygen sensors, spark plugs, and fuel system for potential problems.

To optimize fuel efficiency, maintain proper tire pressure, use premium unleaded fuel, and avoid aggressive driving. Regularly replace air filters and spark plugs, and ensure the fuel system is clean. Lighten the vehicle load and use cruise control on highways. Periodic maintenance, such as alignment checks and engine tune-ups, also contributes to better fuel economy.