Gas, Fuel Efficiency, Vehicles: Myths & Facts Quiz

Aggressive driving can reduce gas mileage by 5 percent on city roads and as much as 33 percent on the highway.

Extra weight wastes gas, and every 100 pounds you carry can reduce gas mileage by 1 percent.

A top-mounted cargo container cuts fuel efficiency by 2 to 8 percent in the city and as much as 25 percent on the highway.

In modern vehicles, cars with an automatic transmission often have the same or better mileage as the same model with manual transmission.

Idling costs between 1 and 2 cents per minute in gas and can use one-third to one-half gallon of gas per hour.

By helping you maintain a constant speed, cruise control saves you gas and money when you're driving on the highway.

Starting a modern vehicle uses as much gas as 10 seconds of idling, so it almost always makes sense to turn your vehicle off rather than leave it on while you're waiting.

Making sure your tires are properly inflated can boost fuel economy by 3.3 percent on average.

Several short trips can actually consume more fuel than one longer trip covering the same total distance. This is especially true if your vehicle is cold when you start it.

Every 1 pound-force per square inch (6,895 pascal) decrease in tire pressure equates to around a 0.03 percent decline in fuel economy.

The best way to warm up a car is to drive it. Allowing the car to sit idle simply wastes gas.

If your vehicle has some problems or fails an emissions test, you can expect to boost fuel efficiency by 4 percent with a proper tuneup.

A 10-percent ethanol blend decreases fuel efficiency by around 3 percent thanks to the lower energy density of the ethanol.

While you should always use premium if your car requires it (check the manual), premium fuel does not improve mileage in the average vehicle.

Fuel economy tests and ratings don't always reflect real-world performance and are designed as a way to compare the relative fuel efficiency of different vehicles.

Replacing a damaged oxygen sensor — a relatively simple fix — can improve fuel economy by as much as 40 percent.

A rear-mounted cargo container only reduces mileage by 1 to 2 percent in the city and 1 to 5 percent on the highway.

The average U.S. household spends around 5 percent of their money on gas, which breaks down to almost $2,000 per household in 2015.

Rolling your windows down has a dramatic effect on fuel economy on the highway. To maximize efficiency, use your air conditioning on the highway and roll your windows down to cool off while driving in the city.

Fuel economy decreases by 12 percent when the temperature drops from 70 degrees Fahrenheit (21 degrees Celsius) to 20 degrees Fahrenheit.

Every 5 miles per hour over 50 miles per hour adds about 12 cents to each gallon of gas you buy.

If you properly maintain your vehicle, you shouldn't expect to find any significant decrease in fuel economy, even after 10 to 15 years of ownership.

Using the recommended motor oil for your vehicle improves fuel economy by an average of 1 to 2 percent -— that's like saving 2 to 3 cents per gallon.

Using your air conditioner can reduce fuel efficiency by as much as 25 percent during the peak of summer.

Thanks to continuous improvements in auto technology, smaller cars aren't always the most efficient. In fact, half of the cars on the Environmental Protection Agency's (EPA) list of most efficient vehicles for 2016 are midsize or larger.

An EPA review of more than 100 devices and products that promise to improve fuel economy found that none actually have any significant impact on mileage.

Because most gas stations store gas underground, the idea that you'll get more gas for your money in the cooler morning hours is no more than a myth.

In a Consumer Reports test, lowering the tailgate or adding a tonneau cover to a pickup actually made fuel economy worse, not better.

The average driver will naturally improve fuel economy by 3 percent when using a driver feedback device, while a person who uses this device primarily to improve mileage can boost efficiency by as much as 10 percent.

In modern vehicles, replacing a dirty air filter may improve vehicle performance, but it's unlikely to improve fuel economy all that much.