On 7/20/2017 5:58 AM, Ed Pawlowski wrote:
On 7/20/2017 7:59 AM, Mad Roger wrote:


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,¡


I'm not doubting their test results but that sounds like a broad blanket
statement. What particular car and engine? Will you get that result
with a Tesla, F-150 and 1987 Chrysler Cordova?

Both AC compressors and auto aerodynamics have improved over the years.
In any case, if it is 85 degrees, I'll have the AC on. My present car
has the best AC of any I've ever had since my first car with ac, a '68
Olds Vista Cruiser I bought in 1971.

I don't use the AC, even in hot weather.

I might be tempted, if it worked.

Here in Seattle, it really is rarely needed, especially if you take care
to park in the shade.