Hyundai Motor America says the addition of two new engines for its refreshed ’10 Santa Fe cross/utility vehicle boosts fuel economy up to 18%.

The ’10 Santa Fe, making its official public debut today at the North American International Auto Show in Detroit, already is available at Hyundai dealers nationwide.

Like its platform-mate, the all-new ’11 Kia Sorento, the Santa Fe receives Hyundai Motor Co. Ltd.’s new Theta II 2.4L 4-cyl. gasoline engine and Lambda II 3.5L V-6.

The 175-hp 4-cyl. Theta II, replacing the base 2.7L V-6 in the ’09 Santa Fe, gets 20/28 mpg (11.8-8.4 L/100 km) city/highway. Both figures represent a 17% increase over the 2.7L’s fuel economy.

The 276-hp Lambda II 3.5L achieves 20/26 mpg (9.0 L/100 km) city/highway, an 18% and 8% increase, respectively, over the 3.3L Lambda I in the ’09 Santa Fe.

All fuel-economy figures are for front-drive models with the 6-speed automatic transmission that replaces the ’09 Santa Fe’s 4-speed and 5-speed automatics.

As with the new Sorento, a 6-speed manual is standard in 4-cyl. versions of the ’10 Santa Fe.

Both new Santa Fe engines are all-aluminum with continuously variable valve timing on intake and exhaust camshafts. The powerplants also boast a variable intake system that “helps cylinders breathe efficiently at low and high rpms,” Hyundai says in a statement.

The other big change for the Santa Fe is redesigned sheet metal. Hyundai calls the ’10 Santa Fe’s styling “more refined” than that of the outgoing model. Bumpers, foglights, side moldings, wheels and grille all get tweaked for ’10.

Inside, the Santa Fe has a factory-installed navigation system, as well as standard Bluetooth, iPod/USB inputs, steering-wheel audio and cruise controls for all grades. Darker interior colors and wood-grain trims also have been added.

The Santa Fe continues to be offered in three trim levels: GLS, SE and Limited.

The 4-cyl. is standard on the GLS, as are heated mirrors, trip computer and driver lumbar support.

The SE offers the 3.5L V-6, and includes a body-colored rear spoiler, leather-and-cloth seats and windshield-wiper deicer.

A trailer prep package, allowing Santa Fes to tow up to 3,500 lbs. (1,588 kg), is standard on SE and Limited V-6 models.

The Limited luxury grade offers either the 4-cyl. or V-6 engine. Added to the standard equipment list are heated front seats, dual-zone automatic temperature controls, an auto-dimming rearview mirror and power sunroof.

The Santa Fe will continue to be built for the U.S. at Hyundai’s Montgomery, AL, plant, also home to the new-for-’10 Sonata sedan.

Pricing has not been released. The ’09 Santa Fe begins at about $22,000 for a GLS and tops out near $30,000 for a Limited grade sans option packages.

Meanwhile, Hyundai displays for the first time in the U.S. its Blue Will plug-in hybrid concept vehicle at the Detroit auto show.

The Blue Will, which debuted at last year’s Seoul auto show, is an experimental vehicle for Hyundai, featuring solar cells on the roof, drive-by-wire steering and lithium polymer batteries.

Hyundai says the model could see its way into production as a hybrid-only vehicle, such as Toyota Motor Corp.’s Prius.

The concept can drive solely on electricity up to 40 miles (64 km) on one charge, with fuel economy touted at 106 mpg (2.2 L/100 km) in plug-in mode.

The Blue Will’s parallel-hybrid features will be seen in the upcoming Hyundai Sonata HEV, due later this year.

cschweinsberg@wardsauto.com