Hip ads for cute cars like the Honda FIT make small models seem perfect for young drivers: They're inexpensive and burn relatively little fuel, making them both economical and eco-friendly. But on average, small cars fare worse in crashes than larger vehicles. "It's the laws of physics," says McCartt. "Small, light vehicles provide less structure to absorb crash energy than larger, heavier ones." In a collision an SUV outweighs a tiny compact by 60 or more -- one reason why 11 of 16 cars with the highest death rates in a recent IIHS study were small models like the Kia Rio or Dodge Neon. But handing over keys of a mammoth SUV or pickup won't make a teen much safer: "The high center of gravity of those vehicles makes them more difficult to handle and more prone to fatal rollovers than other cars, especially for inexperienced drivers," says McCartt.
Give preference to midsize cars, which have enough heft to protect teens in a crash but don't ride so high that they're difficult to control. Avoid vehicles that weigh more than 4,500 pounds, but size isn't everything: Design and safety features also play a role in crash-worthiness, and some small models score well on front, side and rear crash tests. To check safety ratings for individual vehicles, go to iihs.org/ratings.