America’s best hatchback, Honda Fit, carries an EPA sticker on its window that reads 33 mpg city. The next best-seller, Volkswagen GTI, reads 24 mpg city. The spacious Hyundai Elantra carries a rating of 30 mpg city while the oldest hybrid, Toyota Prius, promises a rating of 58 mpg city. Now, compare these figures with sedans. Most struggle to reach 30 mpg city. And midsize SUVs barely manage to touch 20 mpg city. To date, hatches have been go-to vehicles for consumers who prefer their cars to be fuel-efficient. Their lightweight and compact size decreased fuel consumption and enabled better combustion. However, recent reports have suggested that what you see on the window sticker is never the actual figure that you get while driving. Customers who had bought hatchbacks with a 30 mpg city rating saw the return to be 24-city after driving for a few months. This evaporates the fuel-efficiency argument almost instantly but sedans and SUVs suffer from similar deviations as well. The mileage you see and the mileage you get are never the same.
The story behind EPA ratings
The United States Environment Protection Agency or EPA does not actually drive the vehicles on city streets to determine their mileage rating. Instead, they mount the vehicles on motor-driven treadmill-like conveyor belts that run the cars in a particular place. City driving conditions are simulated with the help of a computer and a driver behind the wheel operates the car under test accordingly.
EPA recreates the urban rush-hour in the lab. That means, the car is driven at a minimum speed to 20 mph and a maximum of 56 mph for a duration of 31 minutes. In total, the wheels run for 11 miles with 23 stops mimicking traffic and other halts. The car’s air conditioning is turned off. So are other vehicle accessories. And the rating test begins with a cold engine as if you are restarting your car again after a night in the garage or the day in the parking lot. During the span of the test, the exhaust from the tailpipe is collected through a hose. It is then evaluated to detect the amount of carbon content that points to the efficiency with which fuel is burned. The final readings are adjusted by a factor of 10% to make up for real-world city conditions and a sticker is pasted on the car.
The fault in the system is clearly visible. The simulated conditions never match the real world. Your AC will almost always be running, the car’s body will absorb heat depending on the weather, the air filter will deteriorate over time, and the tires might not be in their top shape. Plus, the actual road is never as smooth as the conveyer belt. All these factors work together to reflect that 6-mpg discrepancy that customers noticed after buying a 30-mpg hatchback.
The deviation is even more when it comes to hybrids. Experts believe that the EPA overestimates their ratings by a factor of 20 as the working of these cars is not similar to standard gasoline vehicles. Within city limits, and at low speeds, hybrids mostly work on the electric engine. You might see a better rating than the one stated if you hardly leave the 20-mph zone. The estimate reverses when you hit the highway. Here, the electric engine hardly operates and you get poorer results.
How to choose?
Having said all that, the mileage figures given out by the EPA is still a reliable guide. You can buy a Honda Fit or a Toyota Prius expecting decent fuel-efficiency figures. Mileage is also largely dependent on your driving habits. Frequent starting and stopping, that too from very high speeds, decrease the overall fuel efficiency to a large extent. Then, comes your maintenance schedules and repair appointments that ensure all the engine and its associated parts are in top shape to allow uninterrupted air and fuel flow. Lastly, the extent to which you load your car also matters. Unnecessary gears under the passenger seats or the cargo hold also adversely affect the city fuel efficiency. On average, expect your hatchback to return a city mileage of 25-mpg. The higher the EPA rating on the car, the better the actual figure naturally. After that, follow all the suggested driving habits and maintain your servicing schedules and you should save a good chunk on your monthly fuel expenses.