A/C Impact on Fuel Economy-A Test

[a2jack]

700 mile round trip to southern Ohio. City, Freeway (mostly I-75). Full gross load plus. 65-75 MPH, 93 dig temp. Air on... 39 MPG. A2Jack

[kwagar]

Originally Posted by msjohnson1974

Just to pick on the methodology of the test a little... Atlanta is over 1000 feet over sea level and Marietta is higher still since it is more towards the mountains. Winter Haven is pretty much at sea level. So on the trip up you were headed up hill and on the trip back, downhill. Just picking on the test conditions...

Now, I have noticed that the AC is dropping my mileage... from 40ish combined to 36ish combined.

I sure wouldn't argue the uphill going North from here and the downhill going south but it would take someone much brighter than I to figure the impact of 1000 feet elevation change over 450 miles, not to mention the ups and downs encountered both directions simply due to the contour of the land.

My test wasn't designed to be scientific or to have a control system. It was simply an observation of what took place and a "for what it's worth" in response to lots of questions regarding fuel mileage results.

[msjohnson1974]

Originally Posted by kwagar

I sure wouldn't argue the uphill going North from here and the downhill going south but it would take someone much brighter than I to figure the impact of 1000 feet elevation change over 450 miles, not to mention the ups and downs encountered both directions simply due to the contour of the land.

My test wasn't designed to be scientific or to have a control system. It was simply an observation of what took place and a "for what it's worth" in response to lots of questions regarding fuel mileage results.

I know, I was just picking on you.

[canon1753]

Doesn't this kind of show the difference in reality between the 07 and 08 EPA testing methodology?

40/45 w/out, 36 with A/C?

[Aerotaz]

I will be glad when I can test my A/C. Seattle was colder than Siberia yesterday and DOT was scraping snow off I-90 coming into town.

<<http://seattletimes.nwsource.com/html/localnews/2004470662_webweather11m.html>>