It seems like everyone on television these days wants you to shop around for auto insurance. Actor Dennis Haysbert says Allstate can save you money. "Flo," with the red lipstick and the bouffant hairdo, is downright perky about Progressive Group. And a Cockney gecko and a pesky stack of googly-eyed cash want you to give Geico a try.

They may all be on to something. Prices in the intensely competitive auto-insurance business are based on so many different factors, and they are calculated in so many different ways, that shopping several different companies really could help you save hundreds of dollars every six months. "Even if you don't change companies, take a test drive and see what's out there," says Ken Ross, commissioner of the Michigan Office of Financial and Insurance Regulation.

Where to Learn More About ...

Insurance scores:;

Car makes and models:

Complaints about insurers:;;

Pricing: the Web site of your state's Department of Insurance

— Source: WSJ research

But doing so will take patience and some understanding of the many pieces that go into your quote. You'll have to find the time to fill out extensive questionnaires about your driving habits and your background or endure the sales pitches of phone operators or agents.

Whether you've had any accidents or traffic violations in the past few years will matter, as well as what car you drive, how many miles you travel each year, the coverage you want and where you drive. Your age will also weigh heavily—and the penalties are as sharp or sharper if you are over 70 years old than if you are under 20.

Here are some other factors to consider before you start comparing.

Your financial behavior matters. Nearly all insurers now look at your credit record because it has proven to be a strong indicator of how likely you are to file a claim. (There's one exception: In California, such use of credit scores isn't allowed).

In fact, Michael Miller, an industry consultant in Carlock, Ill., says credit scores in general are one of the top three factors that insurers consider in determining your rates, alongside where you drive and characteristics like age and gender. Your driving record, while among the top 10 factors, is further down.

The industry uses credit-based insurance scores, which aren't the same as your FICO or other credit scores that banks and mortgage lenders use to determine how likely you are to repay your debts. Insurance scores are based on the same data in your credit report, but they are weighted and calculated differently. The industry contends that 60% or more of consumers pay lower premiums because their credit behavior is factored into the equation.

You can track some of the information insurers use, but insurance scores are hard to penetrate. Make sure your credit reports are accurate by checking them, free of charge, using Once a year, at, you also can get a free copy of your C.L.U.E. auto report, which lists the insurance claims you have filed over the past seven years.

As frustrating as it may seem, different companies use different insurance scores, and many of them consider that proprietary information.

Fair Isaac Corp. , the creator of the FICO credit score, sells insurance scores to companies but not to consumers. The scores generally range from 300 to 900 and are tailored to different state laws. Its Web site says the most important factor in the Fair Isaac score is your payment history, such as delinquencies, collections or a pattern of late payments, followed by how much you owe, including your total debt and what percentage of your credit lines are used. Those two make up 70% of your score, with the rest based on factors like how long you've had your accounts, your number of new credit inquiries and your mix of credit types.

Reed Elsevier sells the ChoicePoint Attract auto insurance score, which ranges from 200 to 997, for $12.95 at But it doesn't explain how it arrives at your number.

In addition, many insurance companies have their own models. According to a filing with the Texas Department of Insurance, which I obtained under an open records request, Allstate's credit score penalizes those whose credit accounts have been more than 60 days late in the past few months or who have opened several new accounts in the past two years. By contrast, Progressive's score penalizes consumers who have fewer than two credit accounts or whose credit is fairly new, as well as those who have missed debt payments in the past 18 months. Still, says James Haas, Progressive's auto research and development manager, the company considers your driving record to be the most important factor in the company's rates.

Regardless of the method used, if your insurer raises your rates or penalizes you for your credit score, it should tell you so and be able to give some explanation for the change.

Compare prices both with insurers that sell directly and those that sell through agents . Prices may vary a lot, and though agents receive a commission, they aren't always more expensive. In fact, Progressive sells both directly and through agents, and it says one isn't always cheaper than the other. But having a mix of prices will help you weigh your options and possibly negotiate better deals.

Loyalty cuts both ways. Car-insurance companies want to win over new customers—but at the same time, they reward you for staying put. Even as you shop around, you'll benefit if you've been with the same company for five years or more. That's because insurers have learned that people who stay with one insurer tend to have fewer claims. Shopping around will help you find the deal that works best for you—even if you stay put.

The discounts are in the details. You'll qualify for discounts if you have multiple policies with the same company. Many companies offer discounts for going paperless, setting up direct deductions from your checking account or paying in full instead of monthly. You might get an early-signing discount of as much as 10% if you agree to switch companies one to two weeks before your current insurance expires, says Steven Armstrong, senior actuary at Allstate. Many insurers offer good-student discounts (B average or better) and breaks for college students who go to school far from home, because they probably aren't driving much.

Price matters, but so does service. The last thing you want after an accident is an insurer that is slow to respond or pay. Once you identify your best deal, check out the company's reputation. Both Consumer Reports and J.D. Power & Associates rank customer satisfaction with insurers. You can research complaints and pricing at the Web site of your state's insurance department, or look up complaint ratios at the National Association of Insurance Commissioners at

Write to Karen Blumenthal at