Dear Tom and Ray:

Recently, on a hot, muggy day as I was driving my mom around on errands, she noticed that the car she and my dad got me (an '87 base-model Nissan Sentra) doesn't have air conditioning. She suggested I look into having an air-conditioning unit put in. I'd like that, except for two things: The car is already underpowered as it is, and I'm afraid an air conditioner would make it worse; and adding an AC unit sounds expensive (I'm on a student's budget). Can you tell me if my fears are valid, or if I'm just the poor, misguided young person I know some old geezer is making me out to be? -- Jonathan

TOM: Hey, I'm not just "some old geezer," kiddo. I'm the old geezer with the answer to your question.

RAY: Your instincts are correct, Jonathan. The air conditioner -- when in use -- does drain power from the engine. So if the engine doesn't have enough power for you now, it'll be worse when it's also running an air-conditioning compressor.

TOM: And it is pricey to install. While most modern cars come "air-conditioning ready" -- meaning they have all of the ducts and wires installed at the factory -- it'll cost you upward of $1,500 to have a dealer get an AC kit and install it for you. And on a 15-year-old car, you'll never get that money back.

RAY: Right. What's the ad going to say? "'87 Sentra. Needs engine, but has new AC!"

TOM: So you're better off just toughing it out, Jonathan. Buy a couple of nice, lightweight, cotton T-shirts and a water bottle, show your mother where the window crank is, and when you buy your next car, remember to get one with air conditioning.