Mazda has a reputation in the United States for making small cars and SUVs that are both fuel-efficient and fun to drive. Mazda design philosophies that represent motion, such as Nagare — roughly translated as "natural motion" — and Kodo — "soul of motion" — have inspired great cars, from the MX-5 to the CX-9. The most recent Mazda paradigm shift has been to Skyactiv technology, which loosely means working toward the most "efficient harmony" possible in a vehicle. The technology is applied to engine, transmission, body and chassis systems with the goal of making vehicles lighter, more efficient and more responsive.

First fully used in the new CX-5, which went on sale earlier this year, this new Skyactiv approach will be used in Mazda's next-generation vehicles. The first of these is the 2014 Mazda6, which debuted at the 2012 Los Angeles Auto Show.

Watch Video:  More details of the new Mazda6

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2014 Mazda Mazda6

What is it? A midsize family sedan designed to compete with sales winners such as the Toyota Camry and Honda Accord.

What's hot? Completely redesigned, the new Mazda6 is larger than its predecessor, with sleek new aerodynamic styling and advanced technology; it should be among the class leaders in fuel economy. Mazda also announced plans to make a Skyactiv diesel engine available for the Mazda6, further improving the company's fuel-economy story.

To bump up the buzz around this new car launch, Mazda plans to race a diesel version of the Mazda6 in the U.S. Grand Am Road Racing series, making its track debut at the 24 Hours of Daytona in January. This will be the first diesel ever to compete in this legendary endurance race.

What's not. With only a 184-horsepower 4-cylinder engine available at launch, this sedan may feel underpowered compared with other midsize sedans on the market.

How much and when. The 2014 Mazda Mazda6 will go on sale in January, followed by the diesel in the second half of 2013. Pricing has not been released.

MSN Autos' verdict: Mazda's passion for driving has always shown in its forward-thinking car designs and on-track performance. However, the Mazda6 has never fully tapped into that success and has not been competitive in the midsize sedan market. We think this new, larger Mazda6 — with its fresh design and impressive fuel economy — should be more successful in that crowded segment, and the diesel offering will help set it apart from the competition.

Read:  2014 Mazda Mazda6: First drive review

Perry Stern's automotive career began 19 years ago as an adviser at a vehicle consulting firm. One of the original staff members of CarPoint, Microsoft's automotive Web site that launched in 1995, he became editor of the site in 2002, which is now known as MSN Autos. Stern has also contributed to MSNBC and various MSN properties in Canada, Japan and Europe.