The new ’13 Subaru Outback and Legacy midsize cars bowing at next week’s New York auto show receive a fuel-economy and performance boost by way of the auto maker’s latest flat-4 engine.

The Outback wagon and Legacy sedan will be fitted with a new 2.5L DOHC “FB” Boxer engine, derived from the 2.0L FB that debuted last year in the revamped Forester cross/utility vehicle.

The 2.5L makes 173 hp and 174 lb.-ft. (236 Nm) of torque in the Outback, vs. the 170 hp and 170 lb.-ft. (230 Nm) rating of the current Outback and Legacy’s 2.5L SOHC Boxer.

The new mill’s big advantage is its “greater low-end torque across a broader speed range,” Subaru says.

Buyers selecting the Legacy 2.5i grade or Outback 2.5i and 2.5i Premium models can opt for a 6-speed manual or second-generation, “quieter and more responsive” Lineartronic continuously variable transmission.

The CVT, which has a 6-speed manual mode and steering-wheel-mounted paddle shifters, is standard on Outback 2.5i Limited models and Legacy 2.5i Limited and Premium sedans.

The 256-hp 3.6L Boxer mated to a 5-speed automatic continues as the 6-cyl. offering for the two new vehicles.

The Legacy 2.5GT, which for ’12 had a turbocharged 2.5L Boxer 4-cyl. making 265 hp, is being discontinued for ’13.

Despite its standard all-wheel-drive system, the CVT-equipped 2.5i Legacy sedan should achieve a front-drive-like 32 mpg (7.4 L/100 km) highway, Subaru says, up from 31 mpg (7.6 L/100 km) in the comparable current model. Combined fuel economy is expected to be 27 mpg (8.7 L/100 km), up from 26 mpg (9.0 L/100 km) in ’12 2.5i CVT models.

A ’13 Outback 2.5i with a CVT should hit 26 mpg combined, Subaru says, up from 24 mpg (9.8 L/100 km) for the outgoing model.

The ’13 Outback and Legacy get Subaru’s new EyeSight driver-assist system, which has a stereo camera with a wider detection angle than more expensive radar-based devices, Subaru says.

Both vehicles have newly designed headlights, grilles, and front bumpers, while the Outback adds new fog lights.

Unspecified improvements to the vehicles’ body, suspension and steering have been made to boost agility and quell noise, the auto maker says, adding the Outback and Legacy’s body roll is cut by up to 40%.

Interior upgrades include “new, more comfortable seat fabric,” as well a lighter, matte wood-grain trim in the Outback and dark, glossy wood-grain trim in the Legacy Limited.

The Outback’s rear crossbar now can be moved further rearward to accommodate kayaks or other long gear, Subaru says.

The standard Outback and Legacy AM/FM/CD audio system now has Bluetooth, an iPod jack and a USB port, as well as audio streaming.

Premium Outback and Legacy grades have an optional Harmon/Kardon 440-watt audio system with XM satellite radio.

Limited grades of both vehicles have available voice-activated GPS navigation, as well as an optional package that includes keyless access and start, 2-position driver-seat memory system, rear air-conditioning vents and a new electro-luminescent gauge cluster with a 3.5-in. (8.9-cm) multi-information color display screen.

cschweinsberg@wardsauto.com