The EPA tests all vehicles sold in the US for fuel economy. Understanding these ratings helps consumers make informed choices and developers build accurate fuel cost calculators.
City vs Highway MPG
City MPG simulates urban driving with frequent stops, accelerations, and lower speeds. Highway MPG reflects steady highway cruising. Combined MPG is a weighted average (55% city, 45% highway), representing typical mixed driving.
Real-World vs EPA Estimates
Real-world fuel economy varies based on driving style, weather, terrain, and vehicle condition. EPA estimates are useful for comparison but actual results typically vary by 10-20%. Aggressive driving, cold weather, and AC use reduce efficiency.
Electric Vehicle Ratings (MPGe)
Electric vehicles use MPGe (miles per gallon equivalent) based on energy content. 33.7 kWh = 1 gallon of gas energy. EVs also show range in miles and kWh per 100 miles for efficiency comparison.
Hybrid Ratings
Hybrids show standard MPG ratings. Plug-in hybrids (PHEVs) show both electric range and gasoline MPG for when the battery is depleted. Total range combines electric and gas capabilities.