JasonT
Posts: 509
Joined: Sun Apr 25, 2010 8:42 am
Location: AZ

Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 11:18 am

I'm sure you're all familiar with the debate over which is better - driving with the windows up and the AC on, or the windows down and the AC off. My understanding is that it really depends on the car, the speed, and the conditions.

I was wondering if the instrumentation on the Leaf is precise enough that one could test this on their own without any additional gadgets. The thought I had was this: Find a flat, straight stretch of road that you can go whatever range of speeds you want to test. Set the cruise control to a speed and run whichever test you want to run (Windows Up, Windows Up AC On, Windows Down). Go back to the beginning of the stretch, and repeat for the other tests. You could then go down or up in speeds for additional data points.

I see that the Energy Usage screen does give the current (hah) kW draw, but the information is given in an "analog" format instead of a straight digital display. This makes it trickier, but I would imagine one could still get a good idea of what their windows up/down point was.

So would this work? Is the information given to the driver granular enough for this test to work? Would the instant miles/kWh gauge work better for this? I am (hopefully) getting my car in April, but until then I have to rely on the kindness of strangers for these kind of things :)

User avatar
abasile
Forum Supporter
Posts: 1922
Joined: Thu Sep 02, 2010 10:49 am
Delivery Date: 20 Apr 2011
Location: Arrowbear Lake, CA

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 11:29 am

Sounds like a good idea for my son's science fair project. Yet another reason for my wife to let me buy the LEAF, so that my older son and I can conduct "experiments" together. :lol:
2011 LEAF at 71K miles, pre-owned 2012 Tesla S 85 at 98K miles
LEAF battery: 9/12 bars and < 49 Ah (-28% vs. new)
Tesla battery: 250+ miles of range (-5% vs. new)

User avatar
GeekEV
Posts: 1825
Joined: Tue Jan 18, 2011 4:11 pm
Delivery Date: 15 Feb 2011
Leaf Number: 0308
Location: NorCal, USA

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 11:38 am

The Mythbusters tested this in one of their episodes and revisited it the next season. Not a LEAF (obviously), but in general the same concept should apply.

http://en.wikipedia.org/wiki/MythBusters_(season_2)#AC_vs._Windows_Down
http://en.wikipedia.org/wiki/MythBusters_(2005_season)#AC_vs._Windows_Down

I'd be willing to give it a shot, but it's too cold right now!

2014 Chevy Spark EV 2LT
2013 Tesla Model S 60kWh[/url]
AV L2 EVSE + kWh meter
9.4kW Solar Array + enphase energy

JasonT
Posts: 509
Joined: Sun Apr 25, 2010 8:42 am
Location: AZ

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 12:58 pm

abasile wrote:Yet another reason for my wife to let me buy the LEAF, so that my older son and I can conduct "experiments" together. :lol:
Hah, yeah, good luck on that one. "Honey, we need to spend $35,000... FOR SCIENCE!"

GeekEV wrote:The Mythbusters tested this in one of their episodes and revisited it the next season.
Yeah, I remember watching one (or both) of those episodes. It's been done by numerous people I'm sure - another one was The Straight Dope

Being that I currently have a convertible which has the top down about 95% of the year, I'm very curious what my "windows down" spot will be. I've gotten the impression it's around 45/50MPH in most vehicles, but I would love to know it instead of just guessing. Plus, it just sounds like a fun thing to try :-)

User avatar
Gonewild
Posts: 1262
Joined: Wed Apr 28, 2010 5:05 pm
Delivery Date: 18 May 2011
Leaf Number: 229
Location: Chandler, AZ

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 1:11 pm

Well if I had to guess
I would say for the LEAF the use of AC will use more power then the air drag will cause the engine to draw more.
What ya think?
Over 25,300 miles Plus - Now Sold/ Lease given back to Nissan 8-25-2012
Ordered Glacier Pearl Nissan Leaf SL eTech Edition on 8/31, Delivered March 1, 2011
POWERED By SunPower 5.16kw PV Solar home 3 Solar water panels.
Reserved 4/20

DaveinOlyWA
Posts: 13281
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Feb 2018
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 2:13 pm

Done plenty of both and the #1 factor by far; driver preference.

I don't care what is more efficient. Some days I just want the wind in my hair
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 11,987 miles, 485 GIDs, 37.6 kwh 110.89 Ahr , SOH 96.00, Hx 115.22
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

User avatar
EVDRIVER
Moderator
Posts: 6472
Joined: Sat Apr 24, 2010 7:51 am

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 4:02 pm

If the LEAF had a proper KW meter you could test this but it does not.

User avatar
garygid
Gold Member
Posts: 12451
Joined: Wed Apr 21, 2010 8:10 am
Delivery Date: 29 Mar 2011
Leaf Number: 000855
Location: Laguna Hills, Orange Co, CA

Re: Windows Up & AC On vs Windows Down - can the Leaf test this?

Fri Feb 25, 2011 10:45 pm

Please, remind me what is wrong with the LEAF's kW meters?

Is it that there are three instead of one for total kW?
See SOC/GID-Meter and CAN-Do Info
2011 LEAF, sold in 2015
2010 Prius, 2014 silver Tesla S
Nissan EVSE, mod to 240/120v 16A
PU: SDG&E
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle

Return to “Range / Efficiency / Carwings”