MPG and Fuel Economy Guide: How to Maximize Gas Mileage

How MPG Is Calculated

MPG (Miles Per Gallon) = Miles driven ÷ Gallons of fuel used. To calculate precisely: fill your tank completely, reset your trip odometer, drive normally, fill up again, and divide miles driven by gallons added to refill.

EPA city vs. highway ratings: City driving uses more fuel due to stop-and-go acceleration and idling. Most drivers achieve 10–15% less than EPA estimates in real-world conditions.

Biggest Factors Affecting Fuel Economy

• Speed: Aerodynamic drag increases with the square of speed. Every 5 mph over 60 reduces fuel economy by ~7%. Driving 75 vs. 60 mph uses ~25% more fuel.
• Aggressive acceleration and braking: Accounts for 15–30% variation in fuel economy. Smooth, anticipatory driving is the single biggest driver behavior impact.
• Tire pressure: Underinflated tires increase rolling resistance. Every 1 PSI low reduces MPG ~0.2%. Check monthly.
• Cold weather: Fuel economy drops 15–24% at 20°F vs. 77°F. Engine warm-up burns more fuel; oil is thicker; cabin heating draws battery power in EVs.
• Air conditioning: Reduces MPG by 5–25% at various conditions. At low speeds, rolling down windows is more efficient; at highway speeds, AC is more efficient than open windows (drag).

Proven MPG Improvement Strategies

• Maintain steady speed using cruise control on highways
• Accelerate gently and coast to stops when possible (anticipate red lights)
• Check tire pressure monthly — add 1–2 PSI above the door sticker spec in winter
• Reduce cargo and roof rack weight — every 100 lbs reduces MPG ~1–2%
• Keep air filter clean — a dirty filter reduces MPG 10%+ in older vehicles