Aiming to attract younger buyers to a model whose current owner base is among the industry’s oldest, Toyota is adding a hybrid powertrain option to the ’13 Avalon sedan, due later this year.

The Avalon Hybrid will achieve 40 mpg (5.9 L/100 km) combined city/highway and will be the first full hybrid-electric vehicle in what Toyota describes as the premium midsize segment, which includes the Hyundai Azera and Buick LaCrosse.

Auto makers recently have started picking up their game in the traditionally conservative family sedan market, revising new models with more luxury features and expressive styling inside and out.

Toyota designers say the new Avalon, unveiled at the New York auto show in April, will be the first example of the auto maker’s corporate push toward more adventurous styling. Toyota is hoping the availability of a hybrid powertrain will further its appeal.

The curvy LaCrosse is available with a mild-hybrid option rated at 29 mpg (8.1 L/100 km) combined city/highway.

The new Avalon will use the same Hybrid Synergy Drive technology as the upcoming ’13 Lexus ES 300h with a few system tweaks. Total output is 200 hp. Power is supplied by a 2.5L Atkinson-cycle 4-cyl. engine mated with a pair of electric motors within the transaxle and 245V nickel-metal hydride battery pack.

The battery is comprised of 204 cells and is located in the trunk, reducing cargo space by several cubic feet.

A power-control unit is located in the engine compartment and houses an inverter, DC/DC converter, a step-up converter that raises voltage to a maximum of 650V and the hybrid-drive electronic control unit, which governs electric-motor operation and regenerative braking. The power-control unit is liquid cooled.

There are three modes of operation: EV, Eco and Sport. The Avalon can operate in EV mode for up to 1 mile (1.6 km) at speeds up to 25 mph (40 km/h) Toyota says.

The other engine choice available is a 268-hp 3.5L DOHC V-6 coupled with a 6-speed automatic transmission that has been revised to provide improved performance and fuel economy.

With 248 lb.-ft. (336 Nm) of torque, the engine is expected to deliver 0-60 mph (97 km/h) in less than seven seconds. Fuel economy is rated at 21/31 mpg (11.2-7.6 L/100 km) city/highway and 25 mpg (9.4 L/100 km) combined.

dwinter@wardsauto.com