I must thank bankrate for doing all the research for me.
Turns out, it really does matter how fast you are going.
At speeds below 40 mph, having the windows down means you are saving fuel despite the drag from the air coming in the windows. This is especially true for stop and go traffic.
If you are one of the few people who still drive between 40 and 55, the results are about equal.
At highway speeds of 55 plus, the drag from the wind can be more than 20%, higher than the 10% loss from air conditioning. A recent consumer reports study may have found this wasn’t an issue, but I’m going with bankrate on this one.
Fans win hands down, because they really don’t lower fuel economy. So keep your windows rolled up and the fans on high at highway speeds. Otherwise, windows down in traffic.
Earthgarage has a note about older cars. Their air conditioners are less fuel efficient and will put more pressure on the gas efficiency.
- A/C or Windows Down: Which Method Will Save You Money? (earthgarage.com)
- MyMove™ – Air Conditioner Buying Guide (mymove.com)
- When Cooling Demand is High So is Your Power Bill – A/C Power Saving Tips (prweb.com)
- CASA needs donations of air conditioners and fans to give to the elderly (al.com)
- World switches on to air conditioning (guardian.co.uk)
- Air conditioner stolen during heat wave (channel3000.com)
- 3 Fuel Economy Myths Debunked (keystoneautoloans.com)
- How To Maintain A Window Air Conditioner (livesportstoday.net)
- Reduce Air Conditioning Costs, Electric Bills (aarp.org)
- Quick Tips for Saving Money at the Pump (savings.com)
- Fuel-Efficient Driving Practices in Time for Summer (redenvelope.com)
- Air Conditioner Buying Guide (familyandchild.wordpress.com)
- Heat Safety – Use your head! (myinstraining.wordpress.com)
- Hope (alexisdimyan.wordpress.com)
- Jerry Kelly Adopts Aerospace Technology, Offers a Low-Cost Alternative To Replacing Air Conditioning and Heating System (prnewswire.com)
- Affordable Comfort Offers Commercial Furnace & Air Conditioners Barrie (prweb.com)
- All About Ductless Air Conditioning (answers.com)