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DISCUSSION => General Topics => Topic started by: carguy101 on August 05, 2010, 11:16:00 AM

Title: What MPG are you getting with a/c?
Post by: carguy101 on August 05, 2010, 11:16:00 AM
I know we can feel a huge difference when we turn on the a/c but how much does your mpg change? It seems to drastically change mine and I have even noticed a difference in power and mpg with just the belt on the compressor. Is there something wrong with the compressor maybe?

TIA
Jeff
Title: What MPG are you getting with a/c?
Post by: jscribble on August 05, 2010, 08:03:31 PM
I think mine drops about 30% with the a/c rocking, but I might also lay into the throttle a bit more. Definitely feel the load when I switch it on. Little motors notice parasitic drag more easily imo. Justification for upgrades right there, make it faster and you'll notice it less!
Title: What MPG are you getting with a/c?
Post by: BlueBMW on August 08, 2010, 11:07:56 AM
Mine drops a lot using the A/C.  I seemed to get 24 to 26 city late winter and spring, but with the A/C I've been getting around 21 this summer.  Highway still seems to get about 32 w/ or without A/C
Title: What MPG are you getting with a/c?
Post by: Matt-B on August 09, 2010, 02:28:33 AM
my last tank. using AC 100 miles out of the 340 miles i got on it. I averaged about 28mpg

no AC, maybe closer to 400 miles on a tank if I grandma drive
Title: Gas Mileage
Post by: Gerta318is on August 09, 2010, 09:37:01 AM
I've been getting about 20 mpg (320 miles to the tank).  I use AC quite a bit and have noticed the drag but not on the fuel economy.
Title: What MPG are you getting with a/c?
Post by: BlueBMW on August 09, 2010, 10:33:19 PM
Quote from: Matt-B;95384
my last tank. using AC 100 miles out of the 340 miles i got on it. I averaged about 28mpg

no AC, maybe closer to 400 miles on a tank if I grandma drive


I must drive my poor little 318 too hard!  I'm lucky to hit 250 sometimes, of course I dont usually wait til the light has been on a few days to fill up.
Title: What MPG are you getting with a/c?
Post by: dkbmxer002 on August 09, 2010, 11:04:47 PM
it's amazing imo how much worse it gets, as well as how much slower it is... hahaha
Title: What MPG are you getting with a/c?
Post by: YetiX on August 10, 2010, 11:31:17 AM
Quote from: BlueBMW;95376
Mine drops a lot using the A/C.  I seemed to get 24 to 26 city late winter and spring, but with the A/C I've been getting around 21 this summer.  Highway still seems to get about 32 w/ or without A/C



Me too. Freeway 32mpg with or without A/C.  Don't really pay attention to city mileage.
Title: What MPG are you getting with a/c?
Post by: longtallsally on August 21, 2010, 04:48:21 AM
Quote from: YetiX;95415
Me too. Freeway 32mpg with or without A/C.  Don't really pay attention to city mileage.


Your AC doesn't work, thought we established that.

I've been getting anywhere from 25-29 with my car.  Driving geography is generally short stints and most all city style in very hilly surroundings.  I drive like a total grandma also except where I'll run the revs ALL the way up for 1 or 2 turns (sweeping on/off ramps).  Otherwise I'm generally shifting prior to 2500 rpm and coast down every hill I can and live on the cruise control even at 50 mph (80kph is the limit in most places outside city/town limits here).

If I have the bike rack on, that is the single largest punch in the gut to fuel economy, as it can cost me up to 4 mpg.  The AC I think I determined costs me around 2 mpg maybe less.  I don't really see much of a difference in power when it is on, but I'm probably not a good example based on how conservatively I drive.

I've got 192k (miles, it is a US spec car) on mine and I've done NOTHING to the motor since I bought it other than the oil pan check and use Mobil 1 oil.
Title: What MPG are you getting with a/c?
Post by: DesktopDave on August 21, 2010, 09:56:32 AM
+1 on the rack.  That murders mileage on my minivan too.

I just kept pulling stuff off the motor to improve fuel mileage...it's only running the alternator now.  Pulling about 200 pounds of cargo seemed to help a bit as well.  I'm strongly tempted to get rid of some insulation next.
Title: What MPG are you getting with a/c?
Post by: longtallsally on August 21, 2010, 04:39:07 PM
Don't do it!  Leave that insulation there, you will regret pulling it.  The DSPO of my car pulled it and there are times when it can get deafening in the cab.  I actually going to put in about 30+ lbs. of sound deadening in the car as I really want to quiet it down.

There's a thread here I subscribed to a while back that discusses the topic of mileage and there is some really good info there.  I'd say once I get some of the stuff on the motor done for mine, I'll jump another couple mpg.