On 7/20/2017 4:59 AM, Mad Roger wrote:
On Wed, 19 Jul 2017 21:19:40 -0700,
Bob F wrote:

Maybe you can answer a question I've long wondered about.

Many cars claim in the owners manual that opening the window uses more
gas than turning on the AC. My 1987 Nissan van even claimed this, with
its almost square front and back. However, if I was going up a steep
hill in hot weather with a full load, it would slow down a lot more from
running the AC than from opening the window. Have you ever tested this
with your test rig? On what kinds of vehicles, and what did you find?
Windows or AC better?

Fuel-Economy Face-Off: Driving With Windows Open or With A/C Running?
http://www.consumerreports.org/fuel-...or-ac-running/
By Consumer Reports, June 18, 2017

Q. Does a car use more gasoline when you drive with the windows rolled down
or the air conditioning turned on?

A. ´We found that on an 85-degree day, running the A/C can reduce fuel
economy by 1 to 4 mpg, depending on the car....[while] the effect of
opening the windows at 65 mph did not measurably reduce fuel economy,¡


Thanks for that article. I really didn't believe the manufacturer's
claim after the steep hill test I mentioned.