Dear Car Talk:

I recently purchased a 2017 Honda CR-V Touring Edition with a four-cylinder turbo engine. The salesman said to let the car run for a full two minutes before and after driving it, to let the turbo heat up and cool down. My brother-inlaw is a mechanic. He’s worked on cars all his life, and he said he’s never heard of this. I don’t want to hurt the car by not following the dealer’s instructions; however, I don’t like adding unnecessary gas emissions into the atmosphere either. Not to mention wasting my time. Since my drive to work is half a mile and most of my driving is in town within a twomile radius of home, I feel the car is idling more than I’m actually driving it. For longer trips, I don’t have a problem with the two-minute cool downs. What is your take on this? I look forward to your comments. — Bonnie

You need to go to a hypnotist and forget you ever met this salesman, Bonnie.

All dealership employees are not equally knowledgeable. And salesmen are hired because they’re good at getting people to buy cars, not because they necessarily know a lot about them. This guy had his headlight firmly implanted in his taillight socket.

In the very early days of commercially available turbos, in the 1970s and ‘80s, you were advised to let the car idle after it was run hard. That would allow the oil to circulate through the turbo and continue to cool it off before you shut off the engine.

The danger, in those days, was that if the turbo was too hot when you shut off the engine, the oil that was in it might dry up and get “coked,” blocking those oil passages like heart disease blocks your arteries. We did replace a bunch of coked turbos with 75,000 miles on them back in those days.

But that’s just not the case anymore. Turbos are better and, perhaps more importantly, oils are better — particularly synthetic oils. And idling to cool the turbo just isn’t necessary at all now.

I mean, if you just finished climbing Pike’s Peak with two mothers-inlaw in the back seat and a trunk full of rocks you stole from the National Parks, you might want to let the car idle for a minute before shutting it down. But for the other 364 days a year, just start the car and drive away, and shut it off when you get to your destination. In fact, if you call

the dealership and ask to speak to the service manager rather than a salesman, that’s probably exactly what he’ll tell you.

So, no more idling, Bonnie. Get out there and enjoy your life.

Dear Car Talk:

Decades ago, when I took driver’s education, we were taught to carefully adjust each mirror before getting underway. I’ve noticed that on long trips, my rearview mirror eventually will move out of adjustment. This is something of a mystery to me. Does my spine compress, or does the car just shake things out of adjustment? Or is there something else at work here? The same problem occurs on all cars I drive: The side mirrors are always OK, but the rearview mirror needs readjustment. This has bothered me for a while, and thought you might have some insight. Thank you! — Brent

Hm. You might have a case of “Mirror Droop,” Brent. This affects older cars where the ball and socket that hold the rearview mirror in place

begin to fail and loosen up, and before you know it, you’re looking at that coffee stain on your right pant leg.

But I’m guessing there’s another factor at work here, because I experience this too, even in newer cars. So I think the problem is related to FBSC — Fat Butt Seat Compression.

Here’s what happens: You get in the car, you’re alert, you’re sitting up straight, you set the mirrors and you drive off. And then ... you relax. You slouch a little bit. The seat compresses a little bit. And 10 minutes into your trip, the rearview mirror is adjusted too high, and you have to fix it.

The same thing is happening to the side-view mirrors, but you don’t notice the change there because they’re adjusted primarily for a side-to-side view, not up and down.

With the rearview mirror, you’re aiming more precisely to see out of one little sweet spot: the rear window. That’s a much narrower target. So when you drop down into your seat half an inch, or an inch, you really notice it.

So I think we just need to consider this phenomenon part of the human condition, Brent. And if Shakespeare were alive today, he’d probably lament it in “A Midsummer Night’s Droop.”

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