Volkswagen is finally dropping its long-serving 2.5-liter gasoline engine from several models, in favor of a more efficient, downsized turbocharged 1.8-liter.

The 1.8 turbocharged, direct-injection four-cylinder develops 170 horsepower, the same as the naturally-aspirated 2.5. However, its 184 pounds-feet torque output is 7 lb-ft more than the 5-cylinder 2.5, developed usefully lower in the rev range.

No exact mileage figures have yet been announced, but Volkswagen estimates a 16 percent highway improvement in the Jetta and 17 percent highway in the Beetle, which also receives the new engine.

That means the manual-equipped Beetle and Jetta should improve from 31 mpg and 33 mpg highway, to around 36 and 38 mpg respectively.

The newly-developed engine, built in Silao, Mexico, will debut in the Jetta and Passat SEL, followed by the rest of the Passat range and the Beetle later in the model year.

Several other changes will debut for the 2014 model year in each vehicle. A sporty GSR model (pictured) joins the Beetle range, while R-Line trim replaces the 'Turbo' model line to differentiate it from the turbocharged 1.8. This uses the same 2.0-liter turbocharged engine as before.

All Jettas now get independent multilink rear suspension and electric (rather than hydraulic) power-assisted steering, which should aid handling and further improve fuel efficiency. A rearview camera is now standard on SEL models and above, while SE, SEL and Premium trims get a new high-resolution mutlifunction display in the instrument cluster.

Similar changes appear on the 2014 Passat, along with a host of small specification changes.

While the die-hard economy fans will still opt for Volkswagen's excellent TDI clean diesel models, improved economy from downsized engines should be a little easier to stick with gasoline now too.

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