2015 Audi A3 TDI Diesel: Fuel Economy Review

The 2015 Audi A3 is the first all-new version of the compact luxury car since it was launched in the U.S. as a 2006 model. And there are a lot of changes.

Most noticeable is its evolution from a five-door hatchback to a four-door sedan, facing it off neatly against the Mercedes-Benz CLA (also a compact, front-wheel-drive sedan).

DON'T MISS: 2015 Audi A3 Review

The understructure is all new, built on a shared VW Group architecture that's also used for the 2015 Volkswagen Golf and the upcoming new Audi TT sports car.

These underpinnings will ultimately spawn dozens of vehicles--including the next VW Passat mid-size sedan and a variety of other Audis, but the A3 sedan came first.

(There will be a hatchback A3 as well, but only for the A3 e-tron plug-in hybrid model, and that car's launch been delayed until roughly a year from now.)

We recently spent a weekend with a 2015 Audi A3 TDI diesel sedan, doing errands in and around the New York City area, to see what its real-world fuel economy was like in a mix of driving.

ALSO SEE: 2016 Audi A3 e-tron Plug-In Hybrid: First Drive

Unlike our usual test cycle, which is about two-thirds highway miles, this one fell more heavily into the "mixed city and suburban" category.

The 2015 A3 TDI is rated at 36 mpg combined (31 mpg city, 43 mpg highway) with its new 150-horsepower 2.0-liter four-cylinder turbodiesel engine and six-speed dual-clutch automatic transmission, the only option available for the diesel.

Over 140 miles, that's exactly what we got: 36.9 mpg on the car's digital display, to be exact.

Which pretty much squares with the idea that diesels generally meet their combined EPA ratings, but can do significantly better when driven largely at highway speeds.