Windows up, AC On vs. Windows down, AC off

[ada43952]

I seem to remember being told that in an ICE vehicle that it's actually more efficient when driving long distances (non-city driving) to drive with the windows up and AC on than windows down and AC off. I think the idea was that the additional drag caused by the open windows would out weigh the added fuel used by the AC.

My question is, does this hold true for EVs, and Tesla's Model S specifically? With the low drag coefficient, is it better to have the AC on and windows up or AC off and windows down?

 

[scaesare]

In my experience as you approach highway speeds the car is more efficient using A/C instead of windows...

 

[jdowell362]

I seem to remember being told that in an ICE vehicle that it's actually more efficient when driving long distances (non-city driving) to drive with the windows up and AC on than windows down and AC off. I think the idea was that the additional drag caused by the open windows would out weigh the added fuel used by the AC.

My question is, does this hold true for EVs, and Tesla's Model S specifically? With the low drag coefficient, is it better to have the AC on and windows up or AC off and windows down?

Yeah I mean no matter what the drag coefficient is, it gets destroyed on every windows are down. All that air coming in is the effect of the car pulling on the air around it while moving. It'll always be better to have the windows up beyond 50ish mph.

 

[supratachophobia]

Mythbusters did this. Low speeds, windows. High speeds, AC.

 

[croman]

AC in my car is far more efficient than heat. I can get well below 290wh/mi at 75mph on days <90F keeping temp at 73F and using AC. When I use windows my wh/mi is more like 315 and its very loud.

 

[supratachophobia]

AC in my car is far more efficient than heat. I can get well below 290wh/mi at 75mph on days <90F keeping temp at 73F and using AC. When I use windows my wh/mi is more like 315 and its very loud.

I have also noticed that watts per mile with AC on being lower at faster speeds than with windows down at said faster speeds.

 

[kev1n]

for me, windows up/ac on all the time. i dont even open the windows anymore since its so loud outside lol

 

[TSLA_maybe]

I see much better wh/m (>30) with windows up/AC on (67F) than windows down/AC off for both in-town and highway driving. Even better when highway driving when cruising at constant 70mph, I've had wh/m of ~270

 

[Naonak]

I've tested it. Same stretch of highway, same day/temp/speed/etc... AC is more efficient than windows down by quite a bit (about 70 WH/mile). I didn't test low speed driving though. This was at ~75mph for 14 miles.

 

[tstafford]

Regardless of WH/mile, I'm rolling with the AC. It's hot as Hades in Nashville.

 

[clostridium]

I've tested it. Same stretch of highway, same day/temp/speed/etc... AC is more efficient than windows down by quite a bit (about 70 WH/mile). I didn't test low speed driving though. This was at ~75mph for 14 miles.

There's no doubt that the AC is more efficient than windows down. The AC doesn't really have a big impact on range to start with - try the calculator on the Tesla website to see how the AC impacts range and it's not a huge amount. My experience on my vehicle is that it's even less than their calculator.

 

[doctorwho]

There's no doubt that the AC is more efficient than windows down. The AC doesn't really have a big impact on range to start with - try the calculator on the Tesla website to see how the AC impacts range and it's not a huge amount. My experience on my vehicle is that it's even less than their calculator.

With a name like Clostridium I'm surprised that you have any need for oxygen

 

[Tangible]

i don't think ICE cars are any different from EVs in this regard. Modern aerodynamics are ruined by open windows. It would be nice if cars came with efficient fresh air intakes, emitting outside air through the AC vents, but this doesn't seem to be available on current vehicles.