Everybody knows that when it comes to car repairs, men get much better deals than women.

Or do they?

It turns out that what "everybody knows" might not always be true in this case. A new study suggests that women can level that playing field in a hurry with a little research -- and in some situations might even do better than men when they make the effort to negotiate.

Mystery shoppers snoop around about car repair prices
The new study was done by researchers at the Kellogg School of Management at Northwestern University working with AutoMD.com, a company that gives consumers information on market prices for car repairs.

AutoMD.com gathers its information using "mystery shoppers" -- trained folks who call up repair shops around the country and ask for estimates on repairs on different kinds of cars. The site averages that information and offers it as a guide for consumers.

The premise of the original study was to measure the effect that shopper knowledge had on car repair quotes. AutoMD's mystery shoppers all asked a specific question: How much would it cost to replace the radiator on a 2003 Toyota Camry?

In some of the calls, the mystery shopper would suggest a price -- sometimes the market-correct price, sometimes a higher one. In other calls, they'd say they had "no idea" what it would cost.

When the callers quoted a price, the overall results were pretty much what you'd expect. If the callers (male or female) quoted a higher price, they got higher-priced estimates from the shops. When callers gave the market-correct price, they got more reasonable estimates.

But then the study took an interesting turn when the callers said they had no clue what it might cost to fix their Camry.

The higher the voice, the higher the estimate
When callers told the repair shops that they had no idea what price to expect cost-wise, the male callers typically got market-correct estimates for the repair -- but the women were quoted much higher estimates.

The researchers don't know exactly why this happened, but they think it might have to do with the shops' expectations: They figure that men have some idea, even if they say they don't -- but women really might not have any clue.

However, that gender difference completely disappears when the women show that they have some idea of what the job should cost, the researchers found. Even if the price they mention is too high, women get the same results that men do – there's no gender difference.

That shows that uninformed female shoppers are at a disadvantage when it comes to getting prices on auto repairs, but that they can easily level the playing field by doing a little research before they call.

But even more interesting is what happened when callers questioned the quoted price of the repair.

Where women outshine the fellows
One of the more unexpected findings of the study had to do with negotiations: When women asked for a discount, they were more successful than their male counterparts.

Many of the shops wouldn't budge from their initial estimates when callers of both genders asked for a price break on the repair work.

However, researchers found that repair shops were much more amenable to giving a discount to female callers: About 35 percent of female callers who asked for a discount were able to get one, versus just 25 percent of the men, the researchers said.

So what's the takeaway for women who need a car repair? Call around. Call several different shops, and use the prices you get in the first calls to guide your conversations as you go. And ask for a discount: You may not get it, but on the other hand, you just might.

And the takeaway for men whose cars need a little work? Consider asking a woman to negotiate with the garage on your behalf.