When you buy a car, whether for cash or with monthly payments, one cost you should consider has nothing to do with those fancy options or dealer rip-offs. And that's how much the car you're about to buy is going to cost you to insure. Let's just say that a cheap sticker price doesn't always translate into cheap insurance.

A recent study by the online website that compares insurance providers, InsWeb.com, found that the cost of car insurance is based on a number of factors, including:

  • The age and driving record of the driver
  •  A combination of purchase price and a model's loss history
  •  An automobile's safety and security features
  •  A record of the model's involvement in insurance claims

That means a car that has a history of expensive liability and comprehensive claims will cost more to insure.

According to InsWeb.com, the cheapest vehicles to insure are the Kia Sedona, Mazda's Mazda5, Ford Escape, Hyundai Santa Fe and Mercury Mariner.

On the other hand, those vehicles topping the list of most expensive to insure are the Acura ZDX, Audi TTS, Audi A5, Cadillac Escalade and the Chevrolet Corvette.

InsWeb compared car-insurance rate quotes for more than 400 models requested by customers between January and September for 2010 model-year vehicles.

Brad Cooper, InsWeb's senior vice president of operations, says the least-expensive cars to buy often are not the cheapest to insure since they're commonly used by younger drivers. Instead, he adds that minivans tend to be the cheapest to insure because of their family-oriented drivers, while sports cars are usually the most expensive to insure.

Other cars that are inexpensive to insure are the Chrysler PT Cruiser, Ford Explorer, Subaru Outback, Kia Optima, and the Chevrolet Equinox.

Among the more expensive cars beyond what we've already mentioned are the BMW Z4, Lexus SC, Jaguar XF, Cadillac STS, 10 Dodge Challenger and the BMW 128i.

The most critical reasons that a car are more expensive to insure are generally the value of the vehicle and the vehicle model's loss history. A vehicle's value directly impacts what an insurance company will need to pay out in the event of a total loss. The loss history reflects a specific model's record of involvement in insurance claims. A model that has a history of expensive liability and comprehensive claims will cost more to insure.

Because driver behavior has such a strong influence on the incidents that cause claims, a model's loss history is directly impacted by the individuals who drive it. That's why the lowest-priced cars available are not necessarily the least expensive cars to insure. Younger drivers often drive inexpensive vehicles, and younger drivers tend to be involved in more insurance claims. Along those same lines, sports cars are generally driven by individuals who want to drive fast, and speed is a factor in many claims.