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-in-law 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 two-mile 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-in-law 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 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.