Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-21-2014, 02:30 PM   #1 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
A/C vs MPG test: impact of air conditioning on fuel economy (2015 Nissan Micra)



Nothing ground-breaking here, but while I was test driving the new Micra, I decided to find out how much of an impact the A/C had on fuel consumption over a range of speeds.

(As an aside, these Micra results would also apply to the 1.6L Versa Note and Versa sedan. Same platform/drivetrain/components.)

I ran a bunch of bi-directional runs at 3 different speeds with the A/C on and off. The fan was left on the 2nd speed for all the runs, just toggling the A/C switch.

Results...

(Note: I graphed it for L/100 km, so those of you used to seeing graphs of "MPG" where the taller bar means better fuel economy, keep in mind it's reversed in this case.)




From: AC vs. MPG: impact of air conditioning on fuel economy tested - Micra-Forum.com


The average fuel consumption increase with A/C on vs. A/C off was 5.9%.

In retrospect, I wish I'd done a couple more 100 km/h runs, since it seemed to show that the A/C impact is smaller at higher speeds & engine loads. Though it makes sense that it would be, since you're covering more ground for a given power draw, plus the engine is probably sitting in a more efficient part of the BSFC map while it's providing that power to the compressor.

Code:
speed   AC      N.      S.      avg L/100 km*

60      off     4      4.1      4.05
        on      4.3    4.4      4.35
        on      4.3    4.5      4.37
        off     4.2    4.1      4.16
                        
80      off     5      4.5      4.75
        on      5.5    4.7      5.10
        off     5      4.5      4.75
                        
100     off     6.3    5.6      5.91
        on      6.6    5.8      6.15

(* Some of the averages are affected by rounded conversions of initial 
readings that were taken in MPG)

Attached Thumbnails
Click image for larger version

Name:	ac-vs-mpg-chart-mpg-too.jpg
Views:	437
Size:	49.8 KB
ID:	15627   Click image for larger version

Name:	ac-vs-mpg.jpg
Views:	459
Size:	49.3 KB
ID:	15628   Click image for larger version

Name:	byc.jpg
Views:	283
Size:	63.5 KB
ID:	15637  
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
The Following 12 Users Say Thank You to MetroMPG For This Useful Post:
aerohead (08-22-2014), ecoTex (08-22-2014), fusion210 (08-22-2014), gone-ot (08-21-2014), jeff88 (08-21-2014), LeanBurn (08-22-2014), mcrews (08-23-2014), PaleMelanesian (08-21-2014), redpoint5 (08-21-2014), sendler (08-23-2014), some_other_dave (08-22-2014), Xist (08-23-2014)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-21-2014, 03:37 PM   #2 (permalink)
Human Environmentalist
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 12,390

Acura TSX - '06 Acura TSX
90 day: 24.19 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 26.68 mpg (US)

Chevy ZR-2 - '03 Chevrolet S10 ZR2
90 day: 17.14 mpg (US)
Thanks: 4,187
Thanked 4,378 Times in 3,353 Posts
At 62 mph, the AC loss drops to 4%. What's more significant to note is that increasing speed from 50 mph to 62 mph results in a 20% drop in mpg.

How were the nifty charts generated?
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
The Following User Says Thank You to redpoint5 For This Useful Post:
MetroMPG (08-21-2014)
Old 08-21-2014, 03:50 PM   #3 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
Excel, then tarted up in Photoshop.

Quote:
What's more significant to note is that increasing speed from 50 mph to 62 mph results in a 20% drop in mpg.
Yessir. I also collected speed vs. mpg numbers for this car, and I'll get around to posting those as well one day.
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
The Following User Says Thank You to MetroMPG For This Useful Post:
aerohead (08-22-2014)
Old 08-21-2014, 04:33 PM   #4 (permalink)
Master EcoModder
 
Join Date: May 2012
Location: USA
Posts: 2,643
Thanks: 1,502
Thanked 279 Times in 229 Posts
Now what everyone really wants to know, can you hypermile so you can have your cake and eat it? Is there a way to drive and have ac without effecting mpg?
  Reply With Quote
Old 08-21-2014, 04:38 PM   #5 (permalink)
Too many cars
 
Gasoline Fumes's Avatar
 
Join Date: Oct 2009
Location: New York State
Posts: 1,568

CRXFi - '88 Honda CRX XFi

Insight 256 - '00 Honda Insight
Team Honda
Gen-1 Insights

Insight 5342 (no IMA) - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 66.3 mpg (US)
Thanks: 1,316
Thanked 781 Times in 465 Posts
Quote:
Originally Posted by Cobb View Post
Now what everyone really wants to know, can you hypermile so you can have your cake and eat it? Is there a way to drive and have ac without effecting mpg?
Use the A/C only going downhill? I did that in a '97 Odyssey and got a record tank while remaining pretty comfortable.
__________________
2000 Honda Insight
2000 Honda Insight
2000 Honda Insight
2006 Honda Insight (parts car)
1988 Honda CRXFi
1994 Geo Metro

  Reply With Quote
The Following 4 Users Say Thank You to Gasoline Fumes For This Useful Post:
aerohead (08-22-2014), chumly (08-22-2014), MetroMPG (08-21-2014), The Other Andy (08-23-2014)
Old 08-21-2014, 06:11 PM   #6 (permalink)
Master EcoModder
 
Join Date: May 2008
Location: Briggsdale, Colorado
Posts: 296

Wildfire - '96 Ford Bronco XL
90 day: 14.88 mpg (US)

Blackford - '96 Ford Bronco XLT
90 day: 20.26 mpg (US)

Y2k - '00 Honda Insight
Gen-1 Insights
Team Honda
90 day: 73.98 mpg (US)

Redford V10 - '01 Ford F250 Lariat
90 day: 15.64 mpg (US)

FireFly - '00 Honda Insight DX
90 day: 69.43 mpg (US)

LittleRed - '00 Honda Insight
Thanks: 3
Thanked 31 Times in 14 Posts
I lose about 3 mpg in my Bronco. I have been turning the A/C on for a couple minutes, then off for about 5 or until the heat gets to be too much. Seems to help MPG wise. Be nice to automate it with a time delay relay or something.
__________________
  Reply With Quote
The Following User Says Thank You to 99metro For This Useful Post:
aerohead (08-22-2014)
Old 08-21-2014, 06:45 PM   #7 (permalink)
EcoModding Lurker
 
Join Date: Jul 2014
Location: MI
Posts: 54

grey panther - '02 Mercury Grand Marquis
Team Panther
90 day: 27.15 mpg (US)
Thanks: 9
Thanked 18 Times in 12 Posts
Run the air just prior, during or instead of braking
  Reply With Quote
The Following 3 Users Say Thank You to tyronasauras For This Useful Post:
aerohead (08-22-2014), chumly (08-22-2014), MetroMPG (08-21-2014)
Old 08-21-2014, 08:17 PM   #8 (permalink)
Master EcoModder
 
Join Date: May 2012
Location: USA
Posts: 2,643
Thanks: 1,502
Thanked 279 Times in 229 Posts
In my Tacoma with the v6 and my 09 scion xb I couldnt tell a diff with ac on or not. In my geo and insight it feels like such a load.

To make your home ac more efficient they have variable compressors. Of course most home ac runs at a constant speed and with enough extra capacity it cycles off and on. With a car its speed varies a hell of a lot and cycles as needed. Many newer cars use an ecu vs high and low psi sensors to cycle the compressor off and on. Plus it works the ac differently if you have the eco mode on or sport. My insight the ac is always colder with eco off and sport mode on addition to the settings. Eco off makes it 1 step colder, sport makes it another.
  Reply With Quote
Old 08-21-2014, 09:13 PM   #9 (permalink)
Master EcoModder
 
Join Date: Aug 2010
Location: Philippines
Posts: 2,173
Thanks: 1,739
Thanked 589 Times in 401 Posts
5.9%? Hell, that's big enough a difference to drive a semi through, given most test results here.
  Reply With Quote
Old 08-21-2014, 09:54 PM   #10 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
Quote:
Originally Posted by tyronasauras View Post
Run the air just prior, during or instead of braking
Quote:
Originally Posted by Gasoline Fumes View Post
Use the A/C only going downhill?
Yup! And yup!

Sounds like we need an Arduino type of project that uses accelerometers/inclinometers to automate the A/C switch.

__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
The Following 2 Users Say Thank You to MetroMPG For This Useful Post:
aerohead (08-22-2014), dirtydave (08-25-2014)
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com