Today’s question from a customer was a good one and reminds us of how little most of us understand our cars.
Chuck R. from Rancho asked:
“My air conditioner has three settings, low medium and high. I know the ac cuts into my gas milage, but I LOVE feeling the arctic blast as I drive around on a hot day. Can I save on gas by setting the ac to ‘Low’?”
Sorry, Chuck. You’re right about the ac reducing your mpg. The compressor puts a drag or “load” on the engine, so it has to work harder. Unfortunately, it’s what is called a constant load, meaning that it turns at the same speed all the time. Your ac’s fan has three speeds, your compressor has one speed. Setting the fan on low means that it will draw a little (very little) less electricity. The effect on your mpg will be too small to measure. You might as well sit back, put the ac on high, and let ‘er rip!