New rules for crash-testing vehicles may change the way safety ratings are doled out to automakers. / Insurance Institute for Highway Safety

Nissan and Volkswagen will be among the automakers waiting somewhat nervously to see how their bread-and-butter midsize sedans come out later this year in a tough new crash test whose first results were introduced this week.

They have reason to be concerned: Only three of the first 11 cars passed the so-called small overlap test, in which the left one-fourth of the front of the vehicle is driven into a hard barrier at 40 mph. Those were all luxury sedans, and the only ones to earn “Good” or “Acceptable” ratings were the 2012 Acura TL, Volvo S60 and Infiniti G.

But by early December, the Insurance Institute for Highway Safety, which came up with the new procedure at its Virginia crash-test facility, will also subject the nation’s popular midsize sedans to the test.

Those will include the redesigned 2013 Nissan Altima, built in that carmaker’s Smyrna plant, and the new 2012 Volkswagen Passat, which is made in the German automaker’s Chattanooga plant. Also to be tested will be the latest generation of the top-selling car in the U.S., the Toyota Camry, along with models such as the redesigned 2013 Honda Accord, Ford Fusion and Chevrolet Malibu.

“The midsize cars are still the heart of the vehicle market and where safety is most important,” said Adrian Lund, president of the institute, which is an independent testing organization funded mostly by auto insurers. “That’s why they’re next on the list.”

Unlike federal tests that crash a vehicle head-on into a wall at 35 mph, and an insurance institute procedure that runs the front 40 percent of a vehicle into a barrier at 40 mph, the new test measures how serious the driver’s injuries might be if the car just barely hits a roadside barrier, such as a tree or a bridge abutment.

The institute says such crashes account for up to a quarter of the 10,000 fatalities that occur each year from head-on collisions.

“It’s certainly a valid test, and it will show which vehicles have adequate protection for the occupants in a crash like this,” said Clarence Ditlow III, executive director of the Washington, D.C.-based Center for Automotive Safety.

“This will fully test the occupant-restraint systems, and determine whether all of the front air bags will go off,” he said. “We should have a full range of tests that cover all of the common crash modes. Some automakers may not like the results, but the reality is that if you don’t test for it, they won’t design their vehicles for it.”

The stakes could be high for those automakers whose vehicles don’t pass, said George Peterson, president of the research firm AutoPacific. And it could be several years before they’re able to redesign the vehicles to perform well.

“In any of the crash testing done by the National Highway Traffic Safety Administration or the (Insurance Institute), it’s really important to consumers that a vehicle does not get a bad rating,” Peterson added.

Whether the redesigned Altima, which went on sale in May, can make a good showing in the test could eventually have an impact on how well it does in Nissan’s quest to have it overtake the Camry as the nation’s sales leader, Peterson said.

But cars already on the market that don’t do well on the test might be able to get a temporary pass from consumers — at least for a while — particularly since the test is so new, he said. “If the new midsize cars meet or exceed existing regulations, that’s what people are going to pay the most attention to.”

While some automakers have objected to the new test, including Mercedes-Benz, whose C-class sedan was among those getting a “poor” rating, others say they will move as quickly as possible to change their designs to meet the revised standard.

For some, it might be as simple as reprogramming side air bags.

While Lund won’t predict how well any of the midsize cars might do on the test, he said the fact that the Infiniti G sedan passed might bode well for the Altima. Infiniti is Nissan’s premium brand, and basic safety engineering should be the same on all Nissan products, he said.

Nissan also would not speculate on how well the Altima and its other Smyrna-built sedan, the Maxima, might do in the tests to be conducted later this fall.

“Nissan shares the (insurance institute’s) commitment to improving vehicle safety and believes that consumers should have information about crash protection so they can make educated buying decisions,” the Franklin-based Nissan North America said in an emailed statement.

But the company has reservations about the test.

“We are receptive to the introduction of the new small overlap testing and are pleased with the overall performance of the Infiniti G sedan,” Nissan said. “However, we believe further research is needed to determine whether the new crash test is representative of small overlap crashes occurring in the real world.”

In the Infiniti G’s test, the front and side air bags deployed, and the crash dummy was not thrust into the deformed area in the right front of the cockpit as it was in vehicles where the side bags didn’t come out, Lund said. That meant the crash dummy didn’t get injured.

“(It) was great for all the injury measurements on the dummy,” Lund said.

Most of the vehicles that failed the new test had already earned the institute’s coveted “Top Safety Pick” designation for 2012, and that probably won’t change for them and others that don’t pass the test for model year 2013, Lund said. Vehicles will be cut some slack in a transitional period.

“We’re considering giving a new designation of something like ‘Top Safety Pick Plus’ for the vehicles that do well on the Small Overlap Test,” he said. “We won’t take Top Safety Pick away from them right away. But in the next year, or certainly the year after, it will be a basic requirement. We expect automakers to improve quickly.”

Contact Tennessean business writer G. Chambers Williams III at 615-259-8076 or cwilliams1@tennessean.com.