Primary reasons for using biofuels such as ethanol or biodiesel are pretty well established: They provide a hedge against dependence on petroleum, and they burn cleaner than gasoline or diesel, leaving a smaller carbon footprint. Given those factors, it's reasonable to expect increased use of such fuels and the cars that can run on them.

What does that mean for car insurance? Right now, there's no blanket answer to that question. However, there is reason for optimism. Some carriers already provide discounts to policyholders who drive hybrid cars that run on gasoline and electricity - it's realistic to expect that automobiles powered by biofuels might ultimately qualify owners for similar breaks.

The best thing to do if you're using biofuels is to contact several providers and seek quotes on coverage, the same way you'd shop for a laptop or a suit or a bed.

It doesn't have to be hassle. Use a website such as autoinsurance.us to get multiple quotes from several providers - as well as help evaluating the estimates. An independent agent can explore the question further of how the fuel type will affect premiums.

Most carriers quote premiums based on a number of factors. Following are some of the factors that have an input into setting rates:

+ Where you live: Each state has different requirements, including minimum liability insurance requirements. That means premiums will vary as well.

+ Your driving history: If you have multiple violations, your carrier will consider you a greater risk than it would if your record were clean. Consequently, you'll pay more for coverage.

+ Your credit score: This one might seem nutty. But insurers say that a good credit score indicates a higher level of responsibility, which translates into a lower risk for them.

+ The type of car you drive: Obviously, the more expensive a car you drive, the more it will cost to insure it.

+ The type of coverage you want: Liability coverage is required in every state. Some states require uninsured/underinsured motorist coverage; others don't. Some coverages, such as comprehensive and collision, are always optional. The coverages you choose will affect your premium.

+ Your deductible: This is the amount you must pay before your policy kicks in. The deductible has an inverse relationship with your premium - the higher the deductible, the lower the premium, and vice versa. One thing to remember is that you'll need to be able to come up with the deductible if you have to file a claim.

The good news is providers offer a number of discounts, based on such factors as having anti-theft devices and airbags, as well as taking approved driver training courses.

These discounts vary widely by state and provider, so ask your agent to check into all the price breaks available. Keep it green, and hopefully you'll save some green, too.