A recent study conducted by J.D. Power and Associates found that since the EPA changed the way it tests vehicles, drivers are finding they’re getting better mileage from their cars than advertised.
Before the EPA updated its methods to more accurately reflect modern driving conditions, drivers consistently reported that they got a combined fuel economy average that was less than the advertised EPA rating.
For instance, in 2007, before the update, drivers said they got an average of 97% of the advertised fuel economy. In other words, 3% worse than advertised. In 2008, after the new testing standards were implemented, drivers said they got 105% of the posted fuel economy.
For drivers who meticulously calculate how much they will spend on gas in a week, this leaves them with a pleasant surprise.
One of the largest jumps in predicted mileage versus actual performance was the vanguard hybrid, the Toyota Prius. Drivers were reporting the Prius underperformed its sticker by 19%. Under the new EPA ratings of 48/45 mpg city/highway, it’s now underperforming by only 6%.
Your Mileage May Still Vary (The New York Times)