The Volkswagen will introduce the third “Newer” Beetle at the Chicago Auto Show. The latest Käfer, which goes on sale this summer, features Volkswagen’s TDI Clean Diesel engine that gives the car an estimated 39 mpg on the highway and 29 mpg in the city. If the Beetle is like other TDI-equipped VWs, the actual mileage may be higher. Jetta owners report hybrid-like results of 43 mpg.

The Beetle TDI’s 2.0-liter turbocharged, direct-injection Clean Diesel engine puts out 140 horsepower and 236 pound-feet of torque. This actually the Beetle’s second U.S. diesel: from 1998 until 2006, the New Beetle was fitted with a 1.9-liter turbocharged four-cylinder diesel engine. The new engine has been engineered to provide lower exhaust emissions and quieter acoustics. One fundamental change was the conversion of the fuel-injection system to a common-rail design. The displacement was also increased by 72cc with a 1.5-mm wider bore.

The engine is mated to either a six-speed manual or VW’s nifty dual-clutch DSG six-speed automatic. DSG combines the ease-of-use of an automatic with the responsiveness and economy of a manual and it works like a charm. The DSG transmission DSG has a Tiptronic® function to permit manual gear selection.

Inside, the Beetle TDI gains a supplementary instrument pod that has oil temperature and turbo boost gauges and a stopwatch. Similar to the original Beetle, the car has an extra glovebox — the käferfach or “Beetle bin” – integrated into the dashboard. The lid folds upward, while the standard glove box opens downward.

There will be three Beetle TDI Clean Diesels from which to choose: TDI; TDI with Sunroof; and TDI with Sunroof, Sound, and Navigation. All three come with power windows with one-touch up/down; cruise control; V-Tex Leatherette seating; the kaeferfach secondary glovebox; Bluetooth®; a leather-wrapped multifunction steering wheel with audio controls; three auxiliary gauges; Keyless entry with push-button start; and a Media Device Interface with iPod cable.

Volkswagen says pricing will be announced closer to the official rollout but expect the base TDI to start in the mid-$20,000 range.