does defrost mode affect mileage? - Toyota Yaris Forums

nikvolkert · 10-08-2010, 01:28 PM

i have noticed that the car runs significantly cooler when it is in the defrost/defog mode rather than the other settings. ( i usually don't even need to turn on the ac even on really warm days).
i just thought that the may be the possibility of the car automatically running the compressor part of the time or something like that.
if this is the case i imagine i should stop leaving it in the defrost/defog mode to save some mpgs.

CTScott · 10-08-2010, 02:18 PM

In that mode the compressor is automatically on (unless you do the DIY to unlink that mode from hitting the switch for AC), so you definitely burn more fuel when the knob is turned that way.

STC · 10-08-2010, 04:36 PM

^ Yeppers!

BailOut · 10-08-2010, 04:55 PM

To avoid the MPG hit but still enjoy some defrosting, simply keep the upper heater vents on and open one front window a bit. A sort of evaporation/sublimation occurs which clears off the windshield.

I have found that it takes a hand or two of opening to clear it but then just a few inches to maintain it.

R2D2 · 10-08-2010, 08:50 PM

Thanks for the tip Brian!

Bluevitz-rs · 10-17-2010, 08:23 AM

I've noticed on my Echo that selecting the foot or lower vents only still sends air up to the windshield, so I never turn it to full defrost unless it's really humid out and the windows won't dry up.

Anyone notice this on the Yaris? I know this little cheat doesn't work on my parent's Matrix.

yaris2010RS · 10-18-2010, 12:32 AM

Quote:

Originally Posted by Bluevitz-rs

I've noticed on my Echo that selecting the foot or lower vents only still sends air up to the windshield, so I never turn it to full defrost unless it's really humid out and the windows won't dry up.

Anyone notice this on the Yaris? I know this little cheat doesn't work on my parent's Matrix.

i will definatly try that in the morning.....

33OH · 10-19-2010, 09:50 AM

Quote:

Originally Posted by Bluevitz-rs

I've noticed on my Echo that selecting the foot or lower vents only still sends air up to the windshield, so I never turn it to full defrost unless it's really humid out and the windows won't dry up.

Anyone notice this on the Yaris? I know this little cheat doesn't work on my parent's Matrix.

Yep, this works. I run the "foot" mode all of the time to defrost the windshield.

yaris2010RS · 10-19-2010, 10:42 AM

i tried mine and some air does go to the window but not alot...... i will try it next time i need the defogger and see if its an acceptable amount of air flow to defog/frost the window

Bluevitz-rs · 10-19-2010, 11:06 AM

yeah it isn't a tonne of air, but I've found that using the A/C to defog the windows, you have to keep using it or the moisture taken out by the A/C core gets sent back into the car the minute you turn it off.

33OH · 10-19-2010, 11:30 AM

Unless you leave it in fresh air mode.

Bluevitz-rs · 10-19-2010, 12:50 PM

Quote:

Originally Posted by 33OH

Unless you leave it in fresh air mode.

No, regardless of using fresh or recirculated air.

33OH · 10-19-2010, 12:52 PM

Oh, I never have to move mine off of Fresh air + Foot even in the off position. It automatically defogs the windows for me. If I change it to re-circulated air, that's when the windows fog up.

Then again I do have a leaky car (water comes up through the floor), so maybe my constant fighting of fog is different than what we're talking about.

Ryu · 10-20-2010, 11:56 PM

I just tried the what so called " foot mode" and it works!! It does however send limited amount of air to windshield to clear up the fog, Is it best to to go for coldest air rather than hot air to clear up the fog on windshield faster?
Will the "foot mode" activate the air conditioning?

Bluevitz-rs · 10-21-2010, 12:18 PM

No foot mode does not. Only the two settings with defrost and defrost/foot. And go with warm air to defog the window. Once the windshield is warm, moisture won't condense on it anymore. Plus, warming cold air lowers the humidity level of the air itself, as cold air can not hold as much moisture as warm air can.

Ryu · 10-21-2010, 10:39 PM

Quote:

Originally Posted by Bluevitz-rs

No foot mode does not. Only the two settings with defrost and defrost/foot. And go with warm air to defog the window. Once the windshield is warm, moisture won't condense on it anymore. Plus, warming cold air lowers the humidity level of the air itself, as cold air can not hold as much moisture as warm air can.

Thanks Bluevitz-rs

10-08-2010, 01:28 PM	#1
nikvolkert Drives: 2008 yaris Join Date: Oct 2010 Location: marietta, ga Posts: 4	does defrost mode affect mileage? i have noticed that the car runs significantly cooler when it is in the defrost/defog mode rather than the other settings. ( i usually don't even need to turn on the ac even on really warm days). i just thought that the may be the possibility of the car automatically running the compressor part of the time or something like that. if this is the case i imagine i should stop leaving it in the defrost/defog mode to save some mpgs.

10-08-2010, 04:36 PM	#3
STC "LibertyRides!" View User's Garage Drives: 2010 Yaris 3Dr LB \| 2020 Stang Join Date: Mar 2010 Location: State College, PA, USA Posts: 576	^ Yeppers! __________________ ~ Mark ~ 2010 Yaris 3-Dr Liftback, 5-Speed Manual, P185/60R 15, Bayou Blue Pearl I Love my YARIS - (Click below to see Gaslog): Most miles Tank: 538 tank/10.148 gal = 53.015 MPG / Most MPG: 54.95 MPG (ethanol) 425 tank/7.73 gal "The evils of government are directly proportional to the tolerance of the people." -- Frank Kent

10-08-2010, 04:55 PM	#4
BailOut Steals terrorist's lunch View User's Garage Drives: 2007 Yaris Liftback Join Date: Mar 2007 Location: Reno, Nevada, USA Posts: 1,299	To avoid the MPG hit but still enjoy some defrosting, simply keep the upper heater vents on and open one front window a bit. A sort of evaporation/sublimation occurs which clears off the windshield. I have found that it takes a hand or two of opening to clear it but then just a few inches to maintain it. __________________ - Brian Share the Road I often carry 2 carpool passengers and mountain bikes or snowboards/skis over a 4,500 foot elevation difference. Click the graphic above to see my detailed mileage logs.

10-08-2010, 08:50 PM	#5
R2D2 Crazy Oil Sniffer Drives: MM 09 Yaris 5 Dr LB "Click" Join Date: May 2009 Location: ME Posts: 498	Thanks for the tip Brian! __________________ "The howl was the sound of God’s casting pot, the morphing of my cells into shape, the forming of oceans out of molten premordial plasma. And I could feel it. I could cry for it. I could cry with it." -The Fitful One

10-19-2010, 10:42 AM	#9
yaris2010RS View User's Garage Drives: no-longer-boosted '10 Yaris Join Date: Nov 2009 Location: Angus, Ontario Posts: 1,891	i tried mine and some air does go to the window but not alot...... i will try it next time i need the defogger and see if its an acceptable amount of air flow to defog/frost the window __________________ If it has boobs or wheels sooner or later your gonna have problems with it

10-08-2010, 02:18 PM	#2
CTScott ULTIMATE View User's Garage Drives: 09 5dr LB, 2x 08 3dr LB Join Date: Oct 2008 Location: USA, CT Posts: 13,460	In that mode the compressor is automatically on (unless you do the DIY to unlink that mode from hitting the switch for AC), so you definitely burn more fuel when the knob is turned that way.

10-17-2010, 08:23 AM	#6
Bluevitz-rs 1NZ-6spd View User's Garage Drives: '05 6-Spd Vitz RS Join Date: Oct 2008 Location: Oshawa, Ontario, Canada Posts: 2,967	I've noticed on my Echo that selecting the foot or lower vents only still sends air up to the windshield, so I never turn it to full defrost unless it's really humid out and the windows won't dry up. Anyone notice this on the Yaris? I know this little cheat doesn't work on my parent's Matrix.

10-19-2010, 11:06 AM	#10
Bluevitz-rs 1NZ-6spd View User's Garage Drives: '05 6-Spd Vitz RS Join Date: Oct 2008 Location: Oshawa, Ontario, Canada Posts: 2,967	yeah it isn't a tonne of air, but I've found that using the A/C to defog the windows, you have to keep using it or the moisture taken out by the A/C core gets sent back into the car the minute you turn it off.

10-19-2010, 11:30 AM	#11
33OH Drives: '08 Yaris Join Date: Oct 2008 Location: Dover, Ohio Posts: 7,606	Unless you leave it in fresh air mode.

10-19-2010, 12:52 PM	#13
33OH Drives: '08 Yaris Join Date: Oct 2008 Location: Dover, Ohio Posts: 7,606	Oh, I never have to move mine off of Fresh air + Foot even in the off position. It automatically defogs the windows for me. If I change it to re-circulated air, that's when the windows fog up. Then again I do have a leaky car (water comes up through the floor), so maybe my constant fighting of fog is different than what we're talking about.

10-20-2010, 11:56 PM	#14
Ryu View User's Garage Drives: Copper Orange Mica Yaris Join Date: Feb 2006 Location: Surrey, BC Posts: 503	I just tried the what so called " foot mode" and it works!! It does however send limited amount of air to windshield to clear up the fog, Is it best to to go for coldest air rather than hot air to clear up the fog on windshield faster? Will the "foot mode" activate the air conditioning? __________________ My Copper Orange Mica Yaris with 9.3lb Kosei K1 TS http://www.yarisworld.com/forums/showthread.php?t=10951 http://www.yarisworld.com/forums/showthread.php?t=13882 http://www.yarisworld.com/forums/sho...180#post472180

10-21-2010, 12:18 PM	#15
Bluevitz-rs 1NZ-6spd View User's Garage Drives: '05 6-Spd Vitz RS Join Date: Oct 2008 Location: Oshawa, Ontario, Canada Posts: 2,967	No foot mode does not. Only the two settings with defrost and defrost/foot. And go with warm air to defog the window. Once the windshield is warm, moisture won't condense on it anymore. Plus, warming cold air lowers the humidity level of the air itself, as cold air can not hold as much moisture as warm air can.

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