Dear Tom and Ray:

I suppose it goes without saying that any father-in-law seems crazy to the son-in-law, and, perhaps more emphatically, the son-in-law seems crazy to the father-in-law (What? This thing hoodwinked my daughter, etc.?) But let me present a specific case that might tend to push the balance in my favor (I'm the son-in-law). To cut to the chase: My father-in-law turns off his truck at every stop. Why? My wife tells me that he insists that he is saving gas. Let me further underline the peculiarity of this behavior. We live in Las Cruces, N.M., a town not associated with traffic congestion. You are not likely to sit idling for more than 5 minutes anywhere at anytime probably 95 percent of the time. My question: Is this loony or what? Also, can you give me some scientific explication on the subject, i.e., what's the effect on miles per gallon; effect on the car; is this an inheritable personality defect? -- Matt

TOM: Matt, this is obviously your first marriage. Because by the second or third marriage (take my word for this, Matt), every man learns that you should never try to get between your wife and her sainted father. That can only lead to trouble.

RAY: Particularly when you happen to have your head up your keister, like YOU do in this case, Matt.

TOM: Your father-in-law is doing a good thing for the planet. Idling is a complete waste of fuel. It increases our dependence on foreign oil, pollutes the atmosphere and puts wear and tear on your engine. Not to mention the squeeze it puts on your bank account.

RAY: So turning off the engine when you're going to be sitting for more than a minute or two is a great thing to do. Most hybrid vehicles do this automatically now. When you come to a stop, the engine shuts down, and the moment you touch the gas pedal again, it instantaneously starts up, so quickly that you don't even notice.

TOM: And at least one energy expert we know suggested that if ALL vehicles shut down automatically at idle, we could cut our fuel consumption by 10 percent. Or about 40 MILLION gallons a day! Still sound loony to you?

RAY: Some people are worried about turning off their air conditioner in the summer, or their heater in the winter. But if you leave the fan blower running, there's enough residual hot or cool air to keep the car at a comfortable temperature while you sit there. Even in five minutes -- which is much longer than the average person usually idles -- the temperature inside the cabin won't change more than a few degrees.

TOM: So here's your to-do list, Matt. First, start shutting off your engine when you're idling -- especially if your wife's in the car. Next, tell your wife that you feel lucky to have married into such a smart family. After that, buy your father-in-law a nice bottle of single malt, sit down with him over a ball game, and ask him if he has any other tips for you.

RAY: And finally, whatever those tips are, don't write a letter in the newspaper calling them loony. Got it, Matt? Good luck.