This is one we're late on posting, but it's significant nonetheless. During the 2010 Detroit Auto Show, Hyundai released details of running updates to its 2010 Hyundai Santa Fe midsize crossover utility vehicle--which is on sale, basically, now.

The big news is that Hyundai has replaced both engines in the formerly all-V-6 Santa Fe, swapping the base V-6 for a four, along with some minor styling and equipment changes. This continues a series of engine changes that started last month at the Los Angeles Auto Show, when Hyundai said it would offer only fours in its redesigned 2011 Hyundai Sonata midsize sedan.

The 2010 Santa Fe retains one V-6, a 276-horsepower Lambda II with 34 hp more than the previous 3.3-liter model. It's a heavier vehicle with a higher tow rating--3,500 pounds--than the Sonata sedan, so V-6 grunt is optional for those buyers who need it. That engine is rated at 20 mpg city, 26 mpg highway.

2010 Hyundai Santa Fe

2010 Hyundai Santa Fe

But the 2010 Santa Fe also adds its first four-cylinder, a 175-horsepower 2.4-liter Theta II engine that outperforms the previous base 2.7-liter V-6 not on only fuel economy (at 20 mpg city, 28 mpg highway, versus 18/24) but also on acceleration.

Like other automakers, Hyundai knows that heavier and more powerful cars get worse gas mileage--and that replacing a lazy V-6 with an efficient high-output four saves weight as well as gasoline.

All 2010 Santa Fe models offer a six-speed overdrive automatic transmission, though the base gearbox on the four-cylinder is a six-speed manual. All-wheel-drive is available with both engines.

The base four-cylinder trim level is the GLS, which offers 17-inch alloy wheels, USB/iPod inputs, power accessories and keyless entry as standard, along with safety features like ABS and stability control.

The V-6 model is the closely related SE, which starts with the GLS equipment and adds  standard six-speed automatic and 18-inch alloy wheels on top.

If you're going for full luxe, the high-end Limited option adds chrome door handles, leather seating, heated front seats, dual-zone climate control and a standard power sunroof. The optional navigation package adds a 6.5-inch touchscreen system to the mix.