Adapting your car’s air circulation in the age of COVID-19

Dear Car Talk: I’m retired but had been driving with Uber for the past couple of years. I haven’t driven since COVID-19 started but plan to resume.

In what position would you recommend that a 2018 Mazda CX-5’s air conditioning system be put to minimize the amount of in-car air being circulated? Thanks. — Jim

Ray: Well, I’d suggest you turn off “recirculate,” Jim.

There are two buttons on the left side of your air conditioning control panel. One has a diagram of air (represented by an arrow) coming into the car from outside the front windshield. That’s the “fresh air” setting.

The other button shows the air in a circle, recirculating inside the car. Don’t press that one.

The recirculate button reuses all but 5% to 10% of the air inside your car. It’s useful when you want to cool the car quickly because you’re not continually introducing new, hot, humid air from outside.

The fresh air setting will introduce much more new air, and that’s what you want. I’m guessing you want to minimize the amount of passenger air you’re breathing. And to be fair, your passengers probably want to do the same since for all they know, you just got back from the Sturgis Motorcycle Rally and Group Hug.

So even better — regardless of the AC settings — open at least two windows. Open your driver’s

window and the window diagonally opposite that, on the passenger side in back. You don’t have to open them all the way, but even by opening them a quarter of the way, you’ll usually create a cross current and move air through the car. Even better, crack all of the windows a quarter of the way, if your passengers are amenable.

That doesn’t mean you have to forgo the air conditioning (or heat). You can run those anyway, even with the windows open, and make the in-car temperature more comfortable.

And if I were you, I’d explain to your passengers exactly what you’re doing and why. I’d say: For your safety and for mine, too, I’m following safety rec