NEW YORK (MainStreet) — Insurance companies ramp up the price of automobile insurance for drivers with poor credit-based insurance scores.

Those drivers pay nearly twice as much or 91% for car insurance compared to consumers with excellent driving scores, according to a new insuranceQuotes.com report.

Consumers who have median credit pay 24% more compared to the drivers with excellent credit. insuranceQuotes.com commissioned Quadrant Information Services to examine how credit affects car insurance premiums. Quadrant calculated rates using data from six large carriers in all 50 states. The assumptions included policy limits of $100,000 for injury liability for one person, $300,000 for all injuries and a $500 deductible on collision and comprehensive coverage.

"Considering all of the factors that go into car insurance rates, credit is actually one of the easiest to control," said Laura Adams, senior insurance analyst for insuranceQuotes.com. "Responsible habits such as paying your bills on time and minimizing debt pay off in many ways, including paying less for car insurance."

Insurance companies utilize many factors to evaluate risk and calculate their premiums, including credit, age, gender, driving records and past claims. Insurers typically use a proprietary scoring model instead of FICO credit scores, which are commonly used by mortgage and credit card companies.

The insurance scores are calculated using information in credit reports such as credit card balances, late payments and credit inquiries. The scores are used to predict the possibility of a future insurance loss, instead of a consumer's creditworthiness, which is what is used in a credit score.

"Consumers should monitor their credit reports at least once per year, get errors corrected and notify property insurers about positive changes," she said. "This could lead to hundreds of dollars in annual savings."

Many consumers are still unaware that their credit history plays a factor in the amount they pay for car insurance, Adams said. California, Massachusetts and Hawaii are the only three states which prohibit the use of insurance scores in setting car insurance rates. Some insurance companies only look at your credit when you are a new customer and do not look to see if your credit has improved or decline, she said. Other companies will check more frequently, such as when you renew annually.

Consumers who have improved their credit history by paying their bills on time should ask their agent to reexamine their history, which could lower their premium, Adams said.

"This presents an opportunity for consumers to save money," she said. "Ask your agent to revisit your credit especially if you have a thin credit file. That is real money in your wallet you can be saving."

Consumers can easily maintain a good credit score by ensuring that they pay their bills on time, said Jeff Golding, CEO of WilliamPaid, a Chicago-based company which allows people to build credit through paying their rent online.

"This shows the importance of maintaining a good credit score," he said. "Your credit score is a reflection of you as a whole – fair or unfair. That is the reality. Insurance companies look at your ability to pay back debt as your level of responsibility.

--Written by Ellen Chang for MainStreet