No brand competes in as many North American racing series as Chevrolet, and the brand uses that to connect with customers and improve its cars in ways that aren’t always obvious, said Jim Campbell, Chevrolet vice president of performance vehicles and motor sports.

Chevrolet will introduce two new performance cars — the SS sedan and Corvette Stingray — this year, and an updated version of the Camaro. All three models compete in racing series. After a period when racing seemed divorced from the cars most automakers sell, demands for lightweight vehicles and more efficient engines that combine performance and fuel economy are bringing street and track closer together, Campbell said.

"We rotate engineers from our production vehicles to the racing programs and back," he said. A few years ago, Matthew Wiles went from working on direct fuel-injection systems for GM’s street cars to developing the turbocharged, direct-injection engines used in Indy racing.

"His expertise helped lead to manufacturer’s and driver’s championships for us last year," Campbell said. Direct-injection, turbocharged engines also play a large role in GM vehicles ranging from the subcompact Chevrolet Sonic to the upcoming 2014 Cadillac CTS luxury sedan. Weight-saving techniques and aerodynamics also transfer from race programs to production cars.

"Racing is a wonderful way to train engineers to move very quickly," Campbell said. "Every seven to 14 days, the green flag drops, whether you’re ready or not. They learn to solve problems fast."

NISSAN’S BIG MONTH: Keep an eye on Nissan. Traditionally the third-seller among Japanese brands, the automaker’s Altima was America’s best-selling midsize sedan last month and displaced Honda.

Nissan has high expectations for 2013. The Versa Note subcompact hatchback joins the lineup soon, and a new version of the Rogue crossover arrives in the fourth quarter.

The Altima’s 37,763 sales beat the perennially top-selling Toyota Camry. The last time that happened was May 2011, when Japan’s tsunami crippled Toyota production. Nissan also outsold Honda last month — 126,623 to 121,938 — the first time that’s happened since it was clearing out the last-generation Altima a year ago.

"It was a great month. We even surprised ourselves," said Jose Munoz, Nissan Americas senior vice president of marketing and sales. "We didn’t expect the Altima to be the No. 1 car in America."

It’s a significant achievement, but Nissan is overly dependent on the Altima, said Edmunds.com senior analyst Michelle Krebs. "It accounts for a huge proportion of their sales. They’ve got to spread their sales over more vehicles."

Munoz expects several new models to achieve that. The Pathfinder, which switched from an off-road-oriented SUV to more fuel-efficient crossover last fall, is selling at nearly triple the old model’s rate.

"We’re in the heart of the segment" with the new Pathfinder, which competes with vehicles like Ford Explorer, Chevy Traverse, Honda Pilot and Toyota Highlander, Munoz said. "You’re going to see greater consistency from us in terms of attacking the heart of the market. The new Rogue and Versa Note both target it."

WOULD A PLUG-IN HYBRID SAVE YOU MONEY? A new website lets buyers calculate their fuel costs with a variety of plug-in hybrids. "My Plug-in Hybrid Calculator," created by the U.S. Department of Energy, lets you tailor results to any plug-in on the market and your personal driving needs.

Choosing the most cost-effective vehicle is no longer a simple matter of high miles per gallon equals low cost, because plug-in hybrids’ cruising ranges vary greatly depending on battery size.

For instance, if you drive 30 miles a day and 12,000 miles a year, gasoline and electricity for a Ford C-Max hybrid would cost you $690 if you had a charger at home, but not at work. A 220-volt charger at work would cut that to $558. But if you drive 70 miles a day, 12,000 miles a year and have no charger at work, your total cost rises to $872 and your gas consumption would more than quintuple from 37 gallons to 198.

You can find the calculator under the "Advanced Vehicles and Fuels" tab at FuelEconomy.gov.