???A/C Effect on MPG???
#21
09-03-2010 | 12:45 AM
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Joined: Oct 2007
Posts: 2,304
From: Illinois
On my third tank of premium. Looking good, but I'm not sure it's the fuel - more simple old technique me thinks. I'll soon go back to regular and catch a look-see before the season changes. Right now I'm not thinking premium is cost effective from the MPG point of view.
#22
09-03-2010 | 01:26 AM
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From: Capital Distric New York
Silver - I've not heard that carbon build-up is an issue w/ the Fit.
Now, with the 275HP northstar engine cadillac has it can be. The solution to 'clearing the carbon' is to perform a WOT [wide open throttle] exercise.
*** I am not suggesting this on the Fit - extreme stress on the engine, not sure the Fit could tolerate it, I'm talking 275HP V-8, so don't be foolish.
*** I post this only because carbon build-up can be an issue with some engines and it's one of the reasons I love the northstar engine. WOT in a cadillac is way too much fun_
Source link: Cadillac Forums: Cadillac FAQ and Technical Reference
What you see out the rear view are clouds of brown smoke billowing behind as you hang on with all you've got.
What you see in the front hall mirror every time you look for the next day is one big sh%&t eating grin_
With the Fit, the ECU is smarter than most understand. It will give you the best return for your driving profile.
Back to on topic time now.
Now, with the 275HP northstar engine cadillac has it can be. The solution to 'clearing the carbon' is to perform a WOT [wide open throttle] exercise.
*** I am not suggesting this on the Fit - extreme stress on the engine, not sure the Fit could tolerate it, I'm talking 275HP V-8, so don't be foolish.
*** I post this only because carbon build-up can be an issue with some engines and it's one of the reasons I love the northstar engine. WOT in a cadillac is way too much fun_
The exercise that I think works best for many things is to select manual 2nd gear on an isolated stretch of expressway. This takes the transmission shifting out of the question if you are worried about hurting it. Start at 55 MPH or so and go to WOT in 2nd gear and hold it until the RPM reaches near the normal shift point - i.e. 6500 for an L37 and 6000 for an LD8. Hold the throttle wide open until the engine reaches, say, 6200 for an STS and then just let completely off the throttle. Leave the transmission in 2nd so that the engine brakes the car and creates some pretty heavy over-run conditions at high vacuum levels. Let it slow until it is about 55 or so and then go to WOT again and repeat. This exercise really loads the rings, allows variable RPM operation at WOT for several seconds continuously, creates heavy over-run which tends to unload the rings and make them move and thus exercise them in the ring grooves and it will blow-out carbon and the exhaust - all without creating a spectical of yourself and attracting the attention of cops. You can do it on most any freeway and stay within the 70-75 MPH range allowable. Once a week like this will keep the engine cleaned out and healthy and is DEFINITELY recommended for the Northstar in particular.
What you see out the rear view are clouds of brown smoke billowing behind as you hang on with all you've got.
What you see in the front hall mirror every time you look for the next day is one big sh%&t eating grin_
With the Fit, the ECU is smarter than most understand. It will give you the best return for your driving profile.
Back to on topic time now.
#23
09-03-2010 | 11:55 PM
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Joined: Oct 2007
Posts: 2,304
From: Illinois
I think Honda could have a carbon problem, because only 3 valves work and the 4 valve doesn't open up until 3500 rpms. If your trying to save gas you drive below 3500 rpm.
Thanks for the link KC. I know Honda motors love to rev and think its a cheap fix to do once in awhile.
Thanks for the link KC. I know Honda motors love to rev and think its a cheap fix to do once in awhile.
#24
10-04-2010 | 04:26 PM
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Joined: Sep 2009
Posts: 158
From: USA
The bad winter gas mileage vs summer is attributed to the gasoline, which is changed slightly from normal "summer" gasoline mixtures.
#26
10-06-2010 | 11:01 PM
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Joined: Oct 2007
Posts: 2,304
From: Illinois
Running richer ('burning more fuel') would lead to the engine running colder. A leaner mixture produces more heat, while using less fuel. But the engine temperature isn't controlled by the fuel mixture...
The bad winter gas mileage vs summer is attributed to the gasoline, which is changed slightly from normal "summer" gasoline mixtures.
The bad winter gas mileage vs summer is attributed to the gasoline, which is changed slightly from normal "summer" gasoline mixtures.
Last edited by SilverBullet; 10-06-2010 at 11:42 PM.
#27
04-22-2011 | 07:50 PM
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Joined: Feb 2010
Posts: 305
From: Winless City
I'll be riding the vehicle pictured below when A/C or rolled down windows is needed 
None the less I was just watching the CBS news and they said using A/C does not really affect your MPG 
Oh really? Even with a Fit? 
None the less I was just watching the CBS news and they said using A/C does not really affect your MPG Oh really? Even with a Fit?
#28
07-11-2011 | 02:35 AM
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Joined: Feb 2011
Posts: 97
From: Southwest US
Outside air temps are now 105 -110 degrees and with air on I'm seeing indicated fuel computer readings hovering between 31 - 33mpg and I'm beginning to wonder if this Fit has an issue. I haven't confirmed actual mpg as of yet. Seems like a radical drop in efficiency. All of this is on 91 octane premium.
#29
07-11-2011 | 05:05 AM
I hope this link maybe help 
Mythbusters' mistakes in AC vs windows down episode — Autoblog Green
AC off, windows up = 11.7 MPG
AC off, windows down = 11.3 MPG
AC on, windows up = 11.7 MPG
Mythbusters' mistakes in AC vs windows down episode — Autoblog Green
AC off, windows up = 11.7 MPG
AC off, windows down = 11.3 MPG
AC on, windows up = 11.7 MPG
Last edited by guailifit; 07-11-2011 at 05:15 AM.
#30
07-11-2011 | 12:24 PM
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Posts: 3,417
From: Capital Distric New York
Good link, what it shows is what happens on this forum so often.
Someone starts out with a simple question and the feedback blows it to pieces and the number of additional variables takes the initial thought out the window.
This thread has held up quite well, thanks to all.
When it's hot I run AC. When I turn on the defroster the AC comes on. I like it that way, it works as it's supposed to. I'm not going to sweat for a few cents a mile.
Oh yea, I'm the OP.
Someone starts out with a simple question and the feedback blows it to pieces and the number of additional variables takes the initial thought out the window.
This thread has held up quite well, thanks to all.
When it's hot I run AC. When I turn on the defroster the AC comes on. I like it that way, it works as it's supposed to. I'm not going to sweat for a few cents a mile.
Oh yea, I'm the OP.
#31
07-11-2011 | 10:53 PM
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Joined: Oct 2007
Posts: 2,304
From: Illinois
Here is some info on AC effect.
http://www.nrel.gov/vehiclesandfuels...02_01_1957.pdf
http://www.nrel.gov/docs/fy00osti/28960.pdf
http://www.nrel.gov/vehiclesandfuels...02_01_1957.pdf
http://www.nrel.gov/docs/fy00osti/28960.pdf
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