NEW YORK – Despite unveiling an all-new Versa subcompact sedan at the auto show here, Nissan remains one of the few full-line auto makers without a conventionally powered car that achieves at least 40 mpg (5.8 L/100 km).

The current Versa is the best-selling lower-small car in the U.S., according to Ward’s data, racking up 30,335 deliveries in the first quarter. The most efficient model is the sedan, with a 4-speed automatic transmission and 107-hp 1.6L 4-cyl. engine rated at 25/33 mpg (9.4-7.1 L/100 km) in city/highway driving.

The new ’12 Versa sedan features an advanced second-generation 1.6L I-4 (codename HR16DE) with two injectors per cylinder. The 109-hp engine boosts fuel economy to 30/37 mpg (7.8-6.3 L/100 km) when mated to the auto maker’s new Xtronic continuously variable transmission.

All-new rival small cars from Chevrolet, Ford, Hyundai and Honda have reached or surpassed a highway rating of 40 mpg, but not Nissan, even with its sophisticated new engine and transmission.

Carlos Tavares, chairman of the Nissan Americas region, says the highway target of 40 mpg is not as important as the combined fuel efficiency, which is 33 mpg (7.0 L/100 km) for the new Versa sedan.

For context, all versions of the Hyundai Elantra, with a 148-hp 1.8L I-4, are rated at 40 mpg on the highway and 33 mpg overall.

"We believe we are at the top level of the segments in which we compete," Tavares tells journalists.

Asked if the next-generation Sentra small car will achieve 40 mpg, Tavares makes no promise. "We will continue to improve step by step all of our models as we have done here with (the) Versa sedan, which is up 5 mpg (2.1 km/L) against the current generation."

The Versa sedan will go on sale this summer with a base price of $10,990, followed later by a hatchback version. Historically, hatchbacks have comprised about 65% of Versa sales.

The new Versa springs from Nissan’s "V" (for versatile) architecture, shared with the Micra/March and next-generation Sentra. The vehicles are built in Aguascalientes, Mexico, for various markets. The new platform uses 20% fewer components while retaining the same 102.4-in. (260-cm) wheelbase.

Tavares says the goal with the new Versa was to take out weight (it is 150 lbs. [68 kg] lighter than before) and keep the price low, while increasing content and standard features.

He also tells journalists Nissan North America is juggling production plans for five future vehicles in a bid to offset the fluctuating yen, a strategy expected to boost domestic vehicle manufacturing while reducing imported parts.

The auto maker is moving production of the Xterra SUV and Frontier pickup from Smyrna, TN, to Canton, MS, to make room in Smyrna for the next-generation Rogue cross/utility vehicle that currently is manufactured in Japan.

An all-new Infiniti product, the JX 7-passenger luxury CUV, also will be built in Smyrna and will go on sale next spring.

By the end of 2012, the Nissan Leaf electric car will be assembled in Smyrna, along with lithium-ion batteries.

Tavares says these changes will boost Nissan production in the Americas from 1.1 million vehicles in 2010 to about 1.7 million units annually within the next few years.

By 2015, Nissan wants to manufacture locally 85% of the vehicles it sells in North America, up from 69% currently. By 2014, the auto maker has set a goal to cut in half the number of parts shipped from overseas, compared with 2010.

After giving the keynote speech at the auto show here, Tavares says it’s "difficult to say" how many new suppliers will be needed in North America to support the domestic manufacturing initiative.

"This is not something we started a few months ago," he says of the effort. "It’s something we’ve been doing the last years. But it’s fair to say that the very strong yen we are facing was an accelerator of this strategy."

tmurphy@wardsauto.com