No more conventional gasoline engines for Volkswagen.

The German automaker will phase out naturally aspirated engines for U.S. models over the next three or four years in favor of an all-turbocharged lineup.

The news came from Mark Trahan, VW’s executive vice president for group quality, in an interview with the Detroit News following an Automotive Press Association event.

VW will replace its three remaining non-turbocharged engines--a 2.5-liter inline-five and two versions of its 3.6-liter V-6--when the models that use each engine come up for redesigns or mid-cycle refreshes, Trahan said.

The process begins with the extinction of the stalwart but venerable inline-five for the 2014 model year.

Replacing the five-banger in the 2014 Jetta, Beetle, and Passat will be a 1.8-liter four-cylinder with turbocharging and direct injection.

The four-cylinder will produce the same amount of power as the aged five: 170 horsepower. But it will boast 7 pound-feet of torque more, for a total of 184, and its torque will peak lower in the rev range.

The smaller engine is also expected to improve fuel economy, although exactly how much will vary by model.

2014 Volkswagen Passat Sport

2014 Volkswagen Passat Sport

The Jetta, when equipped with a five-speed manual transmission, nets 30 mpg combined, compared to 26 mpg for the 2.5-liter model.

Volkswagen will also replace its current 2.0-liter TDI turbodiesel four with a new diesel engine, also displacing 2.0 liters, for the 2015 model year.

The new engine, designated EA288, will have direct injection and more power than the previous diesel. It's essentially the same as the engine VW put in the 2015 Golf GTD.

The EA288 will make its debut in the 2015 Golf, Jetta, Beetle, and Passat.

Why eliminate naturally-aspirated engines? Car makers are turning to turbocharged engines because it allows them to decrease displacement without sacrificing power.

Turbo engines are meant to offer the fuel economy of small displacement engines and the power of larger ones.

Many of the new Volkswagen engines will be made at a new engine plant opened in Mexico last January.

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