How your smartphone can help you save on gas

In this season of rising gas prices, the Environmental Protection Agency wants to make it easier for drivers to use a smartphone to estimate their long-term fuel costs.

Starting with 2013 cars appearing in dealerships now, window-stickers will not only list MPG ratings, but also compare five-year fuel costs for a given model with those for the average vehicle. And by scanning the "Quick Response" code (the two-dimensional barcodes increasingly used to retrieve product information online) on that sticker with your smartphone, you can access and personalize mileage data.

"Shoppers with smart phones can get this data right from the dealer's lot," says Bo Saulsbury, spokesman for the Oak Ridge National Laboratory's National Transportation Research Center, which works on technology for the website overseen jointly by the EPA and Department of Transportation.

For 2012 and older models, you can find data at fueleconomy.gov under the section "Find and Compare New and Used Cars." Information available there and on a car's window-sticker details the estimated annual fuel costs. But it does not show the potential fuel savings compared with those of the average vehicle, nor offer the full range of smartphone features.

In updating its mobile-access website, the government allows you not only to find mileage data from your smartphone, but also to enter personal driving information. You can enter the current price of gasoline, your estimated annual miles driven, and how much of that consists of cruising on the highway versus stop-and-go city driving. (To use the scan function, you may have to download a QR code reader app, with one option available here.)

The new window-sticker and websites will also add the following vehicle information:

-- Greenhouse gas ratings. To see how environmentally sound your vehicle choice might be, 2013 models will show how a car rates on emissions of carbon dioxide and other greenhouse gases that contribute to climate change.

-- Smog ratings. A separate rating covers emissions of pollutants that contribute to smog.

-- New labels for electric cars. These stickers will show the so-called MPGe rating, or the converted equivalent to miles per gallon. It also will estimate kilowatt hours per 100 miles to help you estimate your electricity costs.

In addition, the government's enhanced mobile website can help you with the car you own now. The "Your MPG" section lets you enter your gas-price data right at the pump and calculate your mileage. You can also see how it compares with the mileage ratings and with that of other car owners who use the feature.