QDear Tom and Ray: Here is a somewhat hypothetical ethics question, and since you are the most ethical guys in the business, you get to answer it. Suppose that The Jalopy Garage (not the real name) diagnoses a problem dealing with excessive use of fuel (it could be anything, but this will work). Jalopy Garage then makes the repair, including parts and labor, and tells the customer it is guaranteed for 10 days. Nine days later, the customer comes in and states that the repair not only did not work, but it created a worse situation -- i.e., more wasted gas. Jalopy Garage, after inspection, agrees, and does the work again without charge. (Yeah, I know that might be hard to believe by itself.) However, the customer wants to be reimbursed for the extra wasted fuel during the nine days, saying that the garage, by making the situation worse, is responsible for the difference in what would have been used and what actually was used. So . . . it could be a gallon or 20 gallons -- the question is, should the garage be responsible for the increased loss of fuel? -- Gene

ARAY: Gene, you chiseling weasel! This isn't hypothetical! I'm guessing you asked your mechanic to pay for the gas, and he threw you out, right?

TOM: As well he should have. Most warranties do not cover consequential damages. For instance, if your new car breaks down, and you miss a job interview and end up with a career at Hammertoes Fried Eel instead of Bank of America, the car company will fix your car for free, but it won't cover the difference in salary and perks for the rest of your life.

RAY: Or if you buy a cellphone, and it fails and you miss a call from your mail-order bride from Kamchatka, the company will replace the phone, but not the bride.

TOM: They're responsible for the work they do. And if they messed up the repair, they have to make it right. If it was clearly their fault and the car was disabled because of their mistake, many garages will cover the towing fee, too. But other than the direct mechanical results of their work, you're out of luck, Gene. So, unfortunately, the gas is on you.

Dear Tom and Ray: I was driving with my dad on a road trip to see my nephew graduate from boot camp at Paris Island. The air conditioning was on, and I was cold. I noticed that my dad had the air conditioner set on recirculate, and I suggested that he change it to the fresh-air setting. He and I got into a friendly discussion about this, but there is a steak dinner on the line for the correct answer. I heard that it is best to only use the recirculate or max AC for a short time to initially cool off the car, and then it should be switched to fresh air to keep the air inside from getting stale and polluted. My dad insists that it should stay on recirculate, as this is most efficient. Who is right, and who has to give the other the steak dinner? -- Susan

TOM: Air-conditioning decisions really should be made based on the comfort of the passengers. Neither recirculate nor fresh air is more efficient in terms of how much fuel it uses. On most cars, the compressor does the same amount of work on both settings.

RAY: It's just that when you put it on recirculate, it recirculates the same cabin air (actually, it always lets in some fresh air). It takes the air it has already cooled down from inside the cabin and runs it through the evaporator again, making it even cooler. So in that sense, recirculate DOES cool the car more quickly.

TOM: On the fresh-air setting, the ventilation system brings in much more fresh, outside air, and cools that down. So it takes longer to cool the car that way. But, as you say, it does freshen the air, which might be important, especially if Daddy had one of Mom's bean-onion-garlic burritos for lunch.

RAY: So, recirculate does cool the car more quickly, but once it's cool enough, there's no good reason to leave it on recirculate. You can switch it to fresh air or keep it on recirculate -- whichever keeps you more comfortable.

TOM: So I'd say that, in terms of the bet, we should declare Daddy the winner, because, in recirculate mode, the air conditioner does cool the car more quickly -- and we could interpret that to mean more efficiently. But we're also going to rule that he has to buy you a steak for making you sit there and freeze in the name of efficiency. So you should both enjoy your steaks. And during dinner, talk about something else.

Got a question about cars? Write to Click & Clack in care of The Post, or e-mail them by visiting the Car Talk Web site at http://www.cartalk.com.

2007 by

Tom and Ray Magliozzi

and Doug Berman