Good Question: 'Reply All' AC Vs. Windows Down

MINNEAPOLIS (WCCO) -- Windows up or down for fuel economy? And what's the story with those white flower food packets?

As we enter the early days of summer, Debbie Horsch wanted to know which uses more gas: having the windows open or the air conditioner on?

I've wondered about this myself. The answer is surprising: It's more fuel efficient to run the AC, usually.

When you drive faster than 50 mph, the open windows create a lot of drag on the car. The Society of Automotive Engineers found that efficiency drops at least 20 percent.

On the other hand, using the air conditioner drops fuel efficiency by just 10 percent.

So if you're just driving around town, it's closer to a wash between the two. But if you're driving fast, the AC is the way to go.

Lisa, of Minneapolis, is a smart lady, whotreats herself to a bouquet of flowers every once in a while. And she gets the white packets inside. She wanted to know if plant food really works?

First: what's in it? It's basically trying to recreate conditions that were in the soil, so there are sugars that keep the flower living, along with some other compounds that lower the pH of the water, keeping the water flowing into the stem.

Does it work? Yep. There's been a lot of research on plant food. In a vase, you can get between two and six extra days of life out of your flowers, depending on the type and how you feed them.

The last question comes from Dana in Spicer: How did wisdom teeth get their name?

The third molars have been called "teeth of wisdom" since the 17th Century, and wisdom teeth showed up in the 19th Century.

The teeth push up between the ages of 17 and 20, and the reference was, originally, a joke; because the teeth show up around the time kids became adults -- and achieved wisdom, allegedly.

Of course, now we know that our brains don't fully develop until we are around 25 years old, so wisdom teeth is a pretty good name.

And the longer you keep them, the wiser you become. I still have mine, but you probably guessed that.