There's some truth in that infamous ad slogan: "Fifteen minutes could save you 15 percent or more on car insurance."
Nearly four in 10 Americans who have auto insurance haven't re-shopped to compare prices in at least three years, according to a new report from NerdWallet.com. For a good driver, that misstep amounts to an average loss of $416.52 per year.
But for drivers in some states, the savings from shopping around could amount to two, three or four times that national average. (See state breakdown below.) Delaware residents stand to save the most, an estimated $1,845.59 per year.
To calculate those potential savings, NerdWallet compared the three cheapest rates among large insurers in that state against the average annual rate among all large insurers, weighted by market share in that state.
"If you just happened to choose one of those [most popular] insurers, you might not realize how much you could be saving," said Amy Danise, an insurance expert for NerdWallet.
Ideally, you should re-shop your insurance every year, when the policy comes up for renewal, said Victoria Fillet, a certified financial planner and a co-founder of Blueprint Financial Planning in Hoboken, N.J. That's easy found money to stretch your budget, pay down debt or boost savings for other financial goals.
"These kinds of expenses have a tendency to inch up on us," she said. "If you don't pay attention, you wind up paying more than you really have to. Even if you can afford the higher rate, why pay more than you should?"
You should also look to re-shop when you undergo a life change that could influence that rate or make you eligible for difference discounts, Fillet said. For example, if you move or switch jobs, get married or divorced, buy a new car or add a teen driver to the policy.
Comparing rates doesn't have to be time consuming. Plenty of sites — including NerdWallet, CoverHound.com, Compare.com and Insurance.com, among others — offer tools to help users gauge rates in their area.
Expand your search beyond big-name insurers, said NerdWallet's Danise. Regional and specialty insurers may also offer competitive rates.
Be cautious when factoring in advertised discounts, such as a safe driver deal or a break for combining home and auto coverage. Discount rates can vary by state, or be applicable only on a portion of the bill, she said. Many insurers also have an overall discount cap.
"Don't add them all up in your head," she said. "Call and have [the insurer] do a discount review for you."