How to Calculate Your MPG Rating

With rising fuel prices, it is useful to know how to calculate your MPG rating to determine if your car’s fuel needs are consuming too much of your budget. The MPG or mpg rating of a vehicle is the distance (in miles) that it can travel on one gallon of fuel. The fuel economy of a vehicle is measured in miles per gallon. A vehicle with a higher MPG rating will travel farther on the same amount of fuel as a vehicle with a lower MPG rating.

Is Your Car’s MPG Rating Important?

Your car’s MPG rating measures its fuel economy and efficiency, which is significant, not only to your budget but also to the environment. There are a number of notable reasons for buying a fuel efficient vehicle.

• Reduces your fuel costs
• Reduces carbon dioxide emissions
• Reduces oil dependence costs
• Reduces depletion rate of oil resources

The type of car you have and how you drive it can have a huge impact on your car’s fuel economy.

What Affects Your MPG Rating?

Several factors can have an effect on your vehicle’s mpg rating and related fuel efficiency. Fuel-injection engines and more efficient transmissions will increase a vehicle’s fuel economy. A vehicle equipped with electronic and computerized controls, or a hybrid car will have a higher MPG rating.

Heavier vehicles, vehicles with bigger, more powerful engines and vehicles using an increased accessory load with air conditioning or electronics will have diminished fuel efficiency. It is best to do a mpg comparison of different types of vehicles to find the one appropriate for your needs and budget.

Car mpg ratings – The fuel economy of vehicles in the U.S. are regulated by the Corporate Average Fuel Economy (CAFE) enacted by Congress in 1975. It requires vehicles to meet a set minimum standard for mpg ratings, which as of 2007 is 25 miles per gallon. If the annual fleet of car and truck production of a manufacturer falls below the set standard, the manufacturer is required to pay a penalty. Most passenger cars sold in the United States meet or exceed the 25 mpg CAFE standard.

• Subcompact cars (e.g. Hyundai Accent GS, Scion xD) – average of 30 miles per gallon for the overall (city and highway) MPG rating
• Small cars (e.g. Honda Insight, Toyota Corolla LE) – average of 30 miles per gallon for the overall MPG rating
• Sporty cars or roadsters (e.g. Mini Cooper S, Scion tC) – average of 26 miles per gallon for the overall MPG rating
• Sedans (e.g. Ford Fusion Hybrid, Acura TSX) – average of 24 miles per gallon for the overall MPG rating
• Wagons/Hatchbacks (e.g. Toyota Prius IV, Nissan Cube 1.8 S) – average of 29 miles per gallon for overall MPG rating

SUV, Minivan and Truck mpg ratings – Among first-world nations, the U.S. has some of the weakest standards in terms of CAFE, but they have some of the strictest emissions requirements for pollutants. Some of the higher MPG rated vehicles in Europe would not be able to pass U.S. emissions standards, particularly in California.

• Small SUVs (e.g. Toyota RAV 4, Ford Escape XLT) – average of 22 miles per gallon for the overall (city and highway) MPG rating
• Mid-sized/Large SUVs (e.g. Lexus RX 350, Hummer H3) – average of 18 miles per gallon for the overall MPG rating
• Minivans (e.g. Toyota Sienna XLE, Honda Odyssey EX) – average of 18 miles per gallon for the overall MPG rating
• Pickups (e.g. Chevrolet Colorado LS, Nissan Titan SE) – average of 14 miles per gallon for the overall MPG rating

Motorcycle mpg ratings – With many consumers trading in their gas guzzlers for more fuel efficient vehicles, the number of motorcycle riders has steadily increased. In 2009 Consumer Reports tested the fuel economy of small motor scooters and motorcycles, which they had not done since 1981. For the cycles tested, the MPG rating reached as high as 60 to 100 miles per gallon when ridden at a steady speed.

How to Calculate Your MPG Rating

Once you know the MPG rating for your vehicle, you can calculate how much your monthly budget will need to be adjusted to accommodate a rise in gas prices. With just a few simple steps you can easily calculate your MPG rating for the vehicle you currently drive.

1. Take your vehicle to a gas station and fill it up completely. Before leaving the station record the exact mileage displayed on the odometer. Make sure you are looking at the total mileage on your vehicle, not at the trip odometer. Label this mileage as “Mileage A,” e.g. 26,000 miles.
2. Drive the vehicle as you normally would until the gas tank is down to less than half a tank.
3. Go back to the same gas station and preferably the same pump, to fill your gas tank all the way up again. Record the number of gallons displayed on the pump, that it took to fill your tank all the way. Label this as “Gallons B,” e.g. 7 gallons.
4. Record the mileage before leaving the station. Label this mileage “Mileage B,” e.g. 26,170 miles.
5. Subtract Mileage A from Mileage B to see how many miles you traveled since you last filled up with gas. (26,170 miles – 26,000 miles = 170 miles)
6. Divide your answer by Gallons B or the number of gallons it took to fill up your tank on this visit. (170 miles divided by 7 gallons = 24.3 miles per gallon) The answer will be your vehicle’s MPG rating or in this case 24.3 miles per gallon.

Calculate your MPG rating more than once to get a more accurate number. To figure out how much your budget will be affected by a change in gas prices, divide the number of miles you expect to drive in one week by your vehicle’s mpg rating. Multiply the answer by the price per gallon of gas.

You can use your mpg rating to find ways to increase your fuel efficiency. If you do mostly freeway driving and typically stay around 75 miles per hour, calculate your MPG rating and then try driving 65 miles per hour the following week and calculate the rating again for an mpg comparison.

Tips for Improving Gas Mileage

Your mpg will be better when you spend more driving time on freeways than on city streets. Constantly braking and accelerating with city driving, puts a dent in your fuel efficiency. The optimal rate of speed for most engines is between 30 and 60 miles per hour, and driving at a consistent speed can improve fuel economy by as much as 30 percent. Avoid idling for too long, especially if your vehicle is equipped with a larger engine. Fixing fuel leaks, maintaining adequate tire pressure and performing regularly scheduled maintenance to keep your engine running smoothly, will help improve your vehicle’s MPG rating.