Car ins companies

*New-customer rate for male and female single drivers ages 25, 35, 65, and 75 with excellent credit and a clean driving record in AK, AL, AR, AZ, CO, CT, DE, FL, GA, HI, KY, LA, ME, NH, NM, NV, NY, SC, TN, TX, UT, VA, and WA, the states where all five companies are market leaders.

Lower costs passed on to customers

It's important to note that the premium comparison above is for a group of example policyholders with the exact same profile, who drive the same vehicle and buy the same coverage. So the only difference is the insurance company.

Why is USAA so much less expensive?

"We work very hard to keep administrative expenses low, so we can pass those savings on to our members, " said Rebecca Hirsch, a USAA spokeswoman, who added that USAA's expense ratio, or cost for advertising, sales commissions, and other overhead related to acquiring new customers, is approximately half the industry average.

USAA is not available to everyone. It's open only to members of the U.S. military, honorably discharged veterans, and the families of members. However, USAA estimates that about 60 million people qualify for membership, yet just under half of eligible veterans are aware that USAA exists.

Amica, meanwhile, might seem more pricey than it actually is. The Rhode Island-based insurer is a mutual insurance company, meaning it is owned by its customers. In most states it consistently pays policyholders a dividend at the end of each year. The amount of the dividend is not guaranteed, but it is typically 20 percent and results in a net reduction of the annual premium.

The table below shows Amica's $1, 286 average annual premium for our drivers before any dividend, which places it fourth among the six insurers. We've also adjusted that premium assuming a 20 percent dividend, which reduces it to $1, 029 and moves Amica to second-lowest-priced in the 10 states studied.