The 2014 BMW 328d gets excellent fuel economy. Alex Davies / Business Insider The official EPA fuel economy numbers are in for BMW's new diesel-powered sedan, and they're impressive.

The 2014 328d gets 32 miles per gallon in the city and a whopping 45 mpg on the highway, for a combined 37 mpg.

In comparison, the teeny tiny 2013 Smart for two coupe gets 34 mpg in the city, 38 mpg on the highway, for a combined 36 mpg.

Yes, the new BMW sedan — which will go from 0 to 60 mph in about 7 seconds, according to its German maker — goes farther on a gallon of fuel than the Smart car.

The numbers are a coup for automakers like BMW and Audi, which are both working to bring more diesel cars to the US market. That requires overcoming the classic stereotype of diesels as loud and dirty, but savings at the pump should help persuade buyers.

Compared to the 328d, BMW's standard 2013 328i gets 23 mpg in the city, and 33 mpg on the highways, for a combined 26 mpg.

Filling a tank with diesel is more expensive, however. The most recent price figures from the US Energy Information Administration show a gallon of gasoline costs $3.646, while a gallon of diesel comes out to $3.915.