2011 Infiniti G37 Gas Mileage

The 2011 Infiniti G37, a popular choice in the luxury sports sedan and coupe segment, offered a compelling blend of performance, style, and features. However, like all vehicles, its fuel economy was a significant consideration for prospective buyers. This article provides an in-depth look at the 2011 G37's gas mileage, exploring the technical factors that influenced it, comparing it to its competitors, and discussing real-world performance, reliability, maintenance, and the implications for the future of the automotive industry.

Technical Specifications and Engineering Choices

At the heart of the 2011 Infiniti G37 lies the VQ37VHR engine, a 3.7-liter naturally aspirated V6. This engine is renowned for its smooth power delivery and distinctive exhaust note. Key technical features contributing to its performance, and indirectly affecting fuel economy, include:

Variable Valve Event and Lift (VVEL): This system continuously adjusts valve timing and lift on the intake side, optimizing airflow into the cylinders for varying engine speeds and loads. While primarily designed for performance, VVEL also contributes to improved fuel efficiency compared to traditional fixed valve timing systems.
Sequential Multi-Port Fuel Injection: This precise fuel delivery system ensures optimal fuel atomization and combustion, minimizing wasted fuel.
High Compression Ratio (10.5:1): A higher compression ratio enhances thermal efficiency, extracting more power from each combustion cycle. However, it also necessitates the use of premium fuel (91 octane or higher) for optimal performance and to prevent engine knocking.
Lightweight Construction: The G37 utilized aluminum extensively in its engine block and cylinder heads, reducing overall weight and improving fuel economy slightly.

The G37 was available with two transmission choices: a 6-speed manual and a 7-speed automatic. The manual transmission typically yielded slightly lower fuel economy due to driver variability and less efficient gear ratios for maximizing fuel efficiency. The 7-speed automatic, on the other hand, offered more gear ratios, allowing the engine to operate closer to its optimal efficiency point for a wider range of driving conditions.

EPA Estimates and Real-World Performance

The EPA (Environmental Protection Agency) estimated the fuel economy of the 2011 Infiniti G37 as follows (these figures varied slightly depending on the specific model and transmission):

G37 Sedan (RWD, Automatic): 19 mpg city / 27 mpg highway / 22 mpg combined
G37 Coupe (RWD, Automatic): 19 mpg city / 27 mpg highway / 22 mpg combined
G37 Sedan (RWD, Manual): 17 mpg city / 25 mpg highway / 20 mpg combined
G37 Coupe (RWD, Manual): 17 mpg city / 25 mpg highway / 20 mpg combined
G37x Sedan/Coupe (AWD, Automatic): 18 mpg city / 25 mpg highway / 21 mpg combined

It's important to note that these are just estimates. Real-world fuel economy often differed based on driving habits, road conditions, vehicle maintenance, and even tire pressure. Aggressive driving, frequent stop-and-go traffic, and neglecting routine maintenance could significantly reduce fuel economy. Conversely, careful driving, proper tire inflation, and regular servicing could help drivers achieve figures closer to or even exceeding the EPA estimates. Many owners reported slightly lower fuel economy than advertised, particularly in city driving. Online forums dedicated to the G37 are filled with anecdotal evidence supporting this, with many users reporting average combined fuel economy in the 18-21 mpg range.

Comparison with Alternatives

The 2011 Infiniti G37 competed against a strong field of luxury sports sedans and coupes. Key competitors included the BMW 3 Series, Audi A4/A5, Lexus IS, and Mercedes-Benz C-Class. Here's a brief comparison of fuel economy:

BMW 335i (2011): The 335i, with its turbocharged inline-6, often offered comparable or slightly better fuel economy, particularly in highway driving, while delivering similar or even greater performance. Its EPA estimates were around 20 mpg city / 28 mpg highway.
Audi A4/A5 (2011): The A4/A5, typically with a turbocharged 2.0-liter four-cylinder, generally provided better fuel economy than the G37, especially in city driving. However, its performance was also less exhilarating.
Lexus IS 350 (2011): The IS 350, powered by a 3.5-liter V6, offered similar performance and fuel economy to the G37.
Mercedes-Benz C300 (2011): The C300, with its 3.0-liter V6, typically offered slightly better fuel economy in the city but similar highway mileage compared to the G37.

The G37's fuel economy was generally average for its class, leaning towards the lower end compared to models with smaller, turbocharged engines. However, it compensated with a more engaging driving experience and a potent V6 engine.

Pros and Cons of the G37's Fuel Economy

Pros:

Strong Performance: The VQ37VHR engine provided ample power and a thrilling driving experience, offsetting the relatively average fuel economy for many enthusiasts.
Refined Engine Technology: Features like VVEL and sequential fuel injection contributed to optimizing fuel efficiency, even if not class-leading.
Availability of Automatic Transmission: The 7-speed automatic transmission offered a balance of performance and fuel efficiency.

Cons:

Average Fuel Economy: Compared to some competitors, the G37's fuel economy was not its strongest selling point, particularly in city driving.
Premium Fuel Requirement: The high compression ratio necessitated the use of premium fuel, increasing the overall cost of ownership.
Real-World Discrepancies: Many owners experienced fuel economy below the EPA estimates.

Reliability and Maintenance Tips

The VQ37VHR engine is generally considered reliable, but proper maintenance is crucial for ensuring longevity and optimal fuel economy. Key maintenance tips include:

Regular Oil Changes: Use the recommended synthetic oil and adhere to the recommended oil change intervals.
Proper Tire Inflation: Maintain the correct tire pressure to minimize rolling resistance and maximize fuel efficiency.
Clean Air Filter: A clogged air filter restricts airflow to the engine, reducing fuel economy. Replace the air filter according to the manufacturer's recommendations.
Spark Plug Replacement: Replace spark plugs at the recommended intervals to ensure optimal combustion.
Fuel System Cleaning: Consider using a fuel system cleaner periodically to remove deposits and improve fuel efficiency.
Address Diagnostic Codes Promptly: Any engine codes should be investigated and addressed immediately, as they can indicate issues affecting fuel economy.

Common issues that can affect fuel economy in the G37 include faulty oxygen sensors, a malfunctioning mass airflow sensor, and vacuum leaks. Regular inspections and proactive maintenance can help prevent these issues and maintain optimal fuel efficiency. Furthermore, consistent use of premium fuel is crucial to prevent engine knocking and maintain the engine's designed performance and efficiency.

Future Trends and Automotive Industry Implications

The automotive industry is undergoing a rapid transformation, driven by stricter emissions regulations and increasing demand for fuel-efficient and environmentally friendly vehicles. The era of large-displacement, naturally aspirated engines is gradually fading, replaced by smaller, turbocharged engines, hybrid powertrains, and electric vehicles.

While the 2011 Infiniti G37 represented a peak in the naturally aspirated V6 era, its fuel economy figures are unlikely to be acceptable in the long term. Future luxury sports sedans will need to embrace electrification, lightweight materials, and advanced engine technologies to meet increasingly stringent fuel economy standards.

The move towards electric vehicles (EVs) and hybrid electric vehicles (HEVs) is inevitable. These technologies offer significantly improved fuel economy and reduced emissions compared to traditional gasoline-powered vehicles. Even high-performance vehicles are adopting hybrid and electric powertrains to deliver exhilarating performance while minimizing their environmental impact. The lessons learned from optimizing internal combustion engines, such as the VQ37VHR, are being applied to the development of more efficient hybrid and electric powertrains.

In conclusion, the 2011 Infiniti G37's gas mileage was a compromise between performance and efficiency. While not class-leading, it was acceptable for its time, given its powerful V6 engine and engaging driving experience. However, the automotive industry is evolving rapidly, and future vehicles will need to prioritize fuel efficiency and sustainability to meet the challenges of a changing world. The G37 serves as a reminder of a bygone era, while also highlighting the importance of continuous innovation in the pursuit of a more efficient and sustainable automotive future. The pursuit of efficiency continues to drive innovation, ensuring that future generations can enjoy personal transportation with a minimized environmental footprint.