TOM: You might remember that some months ago, we answered a question about whether a person should take his car to a dealer or to an independent mechanic.

RAY: And, in a nutshell, we said that complicated or unusual problems are better handled by dealers, who see the same kinds of cars over and over again. Whereas more-common repairs would be cheaper at an independent shop.

TOM: We had no real evidence that this was true. It was just based on personal experience and gut feeling. And, as you can imagine, we got hammered by dealers who said that their prices are extremely competitive.

RAY: Well, we decided that the only fair thing to do was do some research. So we did a study, and we came up with statistically significant results, as they say in the research biz.

TOM: And here's what we found: There's no question that, on average, dealers charge more than independents for repairs -- 15 percent more in the case of Honda, and 10 percent more in the case of Dodge (these were the two brands we studied).

RAY: This is not a big surprise. Dealers charge more because they have to. They have big overhead costs. After all, does "Crusty" down the street have a "service adviser" in a white lab coat who writes up the repair orders? Does he have a waiting room with doughnuts and coffee, or a van that takes you to work? Loaner cars? No.

TOM: But if those things aren't important to you, you can save a significant amount of money by going to an independent repair shop.

RAY: Here's what we did: We chose two average vehicles -- a 1996 Dodge Intrepid and a 1996 Honda Civic -- and four common repairs:
-- Replace the timing belt and water pump
-- Replace front brake pads and rotors
-- Replace front and rear struts (shocks)
-- Replace the alternator

TOM: Then we commissioned Paul Murky and Murky Research to survey both dealers and independent repair shops and ask for the price to do the repairs on each of the vehicles. We got prices from 158 dealers and repair shops around the country.

RAY: We should add a disclaimer: Obviously, we did not actually take these cars to any of the shops, so we don't know if they would actually do these repairs for the prices quoted to us. We also don't know if they would have pressured us into doing additional repairs once they had our cars. But buying 158 cars to do the real test was a little beyond our budget, so we had to rely on their estimates for this study.

TOM: And here are the national numbers (regionally, things get more interesting -- but more on that next week): For Honda, the average cost of the repairs at all of the Honda dealers was $2,116. The average for the same repairs at the independent shops was $1,796. That's a difference of $320, or about 15 percent.

RAY: For Dodge, the average cost of the repairs at a Dodge dealer was $1,998. At the independent shops: $1,790. The difference is $208, or about 10 percent.

TOM: But that's just the national overview (you can get more details on our Web site, the Car Talk section of www.cars.com). Next week, we'll tell you about some very interesting findings about prices in different parts of the country.