2007 Infiniti G35 Gas Mileage

The 2007 Infiniti G35, a cornerstone of Infiniti's early 2000s lineup, offered a compelling blend of performance and luxury. However, for potential buyers and current owners alike, a key consideration remains: fuel economy. Understanding the real-world gas mileage of the '07 G35 is crucial for budgeting and overall ownership experience. This article delves into the fuel consumption figures, factors affecting them, and provides practical advice for optimizing efficiency.

2007 Infiniti G35: Official EPA Fuel Economy Ratings

The Environmental Protection Agency (EPA) provides standardized fuel economy ratings, serving as a baseline for comparison. However, remember that these are estimates achieved under controlled laboratory conditions and may not perfectly reflect everyday driving.

For the 2007 Infiniti G35, the EPA ratings varied slightly depending on the specific model and drivetrain configuration:

G35 Sedan (Rear-Wheel Drive, Automatic): 19 MPG City / 26 MPG Highway / 22 MPG Combined
G35 Sedan (Rear-Wheel Drive, Manual): 17 MPG City / 25 MPG Highway / 20 MPG Combined
G35 Sedan (All-Wheel Drive, Automatic): 18 MPG City / 25 MPG Highway / 21 MPG Combined
G35 Coupe (Rear-Wheel Drive, Automatic): 19 MPG City / 27 MPG Highway / 22 MPG Combined
G35 Coupe (Rear-Wheel Drive, Manual): 17 MPG City / 25 MPG Highway / 20 MPG Combined

These figures are based on the 2007 EPA testing methodology. It's worth noting that the EPA revised its testing procedures in later years, which might result in slightly different numbers for the same vehicle if tested today.

The Engine: Heart of the Matter

The 2007 G35 is powered by Nissan's renowned VQ35HR engine, a 3.5-liter V6 known for its smooth power delivery and relative reliability. The "HR" designation stands for "High Revolution" and "High Response," indicating improvements over previous VQ engines. This engine delivers a healthy dose of horsepower, typically around 306 hp, which inevitably impacts fuel consumption. It's a trade-off: you get the performance, but you also need to feed the beast.

The engine's design incorporates features like continuously variable valve timing (CVTCS) and direct ignition, which contribute to both performance and fuel efficiency. However, these technologies are primarily geared towards maximizing power output, meaning the G35 isn't inherently designed for hypermiling.

Real-World Fuel Economy: Bridging the Gap

While EPA ratings provide a starting point, real-world gas mileage often differs. Several factors influence fuel consumption under normal driving conditions:

Driving Habits: Aggressive acceleration, hard braking, and high speeds significantly decrease fuel economy. Conversely, smooth acceleration, maintaining a steady speed, and anticipating traffic flow improve efficiency.
Traffic Conditions: Stop-and-go traffic is a fuel economy killer. Idling consumes fuel without covering any distance. Highway driving generally yields better mileage.
Vehicle Maintenance: Neglecting routine maintenance, such as air filter replacement, spark plug changes, and oil changes, can negatively impact fuel efficiency. Clogged air filters restrict airflow, forcing the engine to work harder. Worn spark plugs can lead to incomplete combustion.
Tire Pressure: Underinflated tires increase rolling resistance, requiring the engine to exert more energy to maintain speed. Always maintain the recommended tire pressure as indicated on the doorjamb sticker.
Fuel Quality: Using the recommended octane fuel (premium is often recommended for optimal performance in the G35, though not strictly required) can contribute to slightly better fuel economy. Lower-octane fuels may cause the engine to adjust its timing, potentially reducing power and efficiency.
Load and Passengers: Carrying heavy loads or multiple passengers increases the vehicle's weight, requiring more energy to move.
Weather Conditions: Extreme temperatures, both hot and cold, can affect fuel economy. Cold weather increases engine friction and reduces tire pressure, while hot weather can lead to increased air conditioning usage, which draws power from the engine.

Online resources, such as Fuelly.com, provide user-submitted data on real-world gas mileage for various vehicles, including the 2007 Infiniti G35. These figures can offer a more realistic expectation of what to expect in daily driving.

Troubleshooting Poor Gas Mileage

If your 2007 Infiniti G35 is experiencing significantly lower fuel economy than expected, consider these troubleshooting steps:

Check for Diagnostic Trouble Codes (DTCs): Use an OBD-II scanner to check for any engine-related fault codes. These codes can pinpoint issues that are affecting fuel efficiency. Common culprits include faulty oxygen sensors, mass airflow sensors, and catalytic converters.
Inspect the Air Filter: A dirty or clogged air filter restricts airflow, reducing engine efficiency. Replace the air filter according to the manufacturer's recommended schedule.
Check Tire Pressure: Ensure that all tires are properly inflated to the recommended pressure.
Inspect Spark Plugs: Worn or fouled spark plugs can lead to incomplete combustion and reduced fuel economy. Replace spark plugs according to the manufacturer's recommended schedule.
Check for Fuel Leaks: Inspect the fuel lines, fuel tank, and fuel injectors for any signs of leaks. Fuel leaks are not only a fire hazard but also a significant source of fuel waste.
Evaluate Driving Habits: Analyze your driving habits and identify areas where you can improve fuel efficiency. Avoid aggressive acceleration, hard braking, and excessive idling.
Consider a Professional Inspection: If you've exhausted the above troubleshooting steps and are still experiencing poor gas mileage, consult a qualified mechanic for a professional inspection. They can diagnose more complex issues and recommend appropriate repairs.

Maintenance for Optimal Fuel Efficiency

Regular maintenance is crucial for maintaining optimal fuel efficiency in your 2007 Infiniti G35. Adhere to the manufacturer's recommended maintenance schedule, which includes:

Oil Changes: Regular oil changes with the correct type of oil are essential for engine lubrication and performance.
Air Filter Replacement: Replace the air filter according to the recommended schedule.
Spark Plug Replacement: Replace spark plugs according to the recommended schedule.
Fuel Filter Replacement: Replace the fuel filter according to the recommended schedule to ensure a clean fuel supply.
Tire Rotations: Regular tire rotations promote even tire wear and maintain optimal rolling resistance.
Wheel Alignments: Proper wheel alignment reduces tire wear and improves fuel efficiency.
Throttle Body Cleaning: Over time, the throttle body can accumulate carbon deposits, restricting airflow and reducing engine efficiency. Cleaning the throttle body can improve performance and fuel economy.
Oxygen Sensor Replacement: Oxygen sensors play a crucial role in fuel management. Replace them according to the recommended schedule.

The Bottom Line

The 2007 Infiniti G35 offered a compelling driving experience, but fuel economy wasn't its strongest suit. Understanding the factors that influence gas mileage, practicing fuel-efficient driving habits, and maintaining your vehicle diligently can help you maximize fuel economy and minimize your operating costs. While it won't rival a hybrid in fuel efficiency, a well-maintained G35 can still deliver acceptable mileage for its class, especially on the highway. Remember that the joy of driving often comes with a price, and in the case of the G35, that price includes a slightly thirstier engine than some of its competitors.