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Honda Civic Real World MPG

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Comments

  • dantzdantz Posts: 49
    Has anyone determined the Civic air conditioner's effect on both performance and mileage? Because I can't feel any difference in acceleration whether my 2008 Civic's AC is on or off. I realize that this model of Civic has a somewhat underpowered air conditioner, but it must also be remarkably efficient, as it seems to get the job done without any noticeable drag on the engine.

    With my old Corolla I had the habit of temporarily turning the AC off whenever I needed an extra boost of power, for example on uphill freeway on-ramps, but with the Civic I can no longer tell the difference, so I just leave the AC on.

    All I can think of is to do some test accelerations from zero to 60 with the AC both on and off to see if there is much difference in the elapsed time or the distance required. (I'll try doing this and then report back.)

    I'd also be interested in knowing if anybody with a ScanGauge (or a similar device) has checked the instantaneous mileage in order to determine the AC's effect on highway mileage, while leaving the windows up. All I have found so far is comparisons between AC with windows up, and no AC with windows down, but that comparison is flawed because they are changing two elements at once. I think leaving the windows up and keeping the fan on while switching the AC on and off would be a fairer test.
  • thegraduatethegraduate Posts: 9,731
    In almost any car these days (even my old '96 Honda), when the throttle is pushed hard, the A/C will momentarily cut-off on its own in order to channel more power to the wheels instead of the A/C. My dad's 2007 Civic is no different. On a hot day, get on the throttle hard while you feel the A/C blowing on your face. You'll feel a difference I'd bet.

    Hope that helps. :)
  • dantzdantz Posts: 49
    Yes, I've considered that possibility, but as far as I can tell the AC appears to stay on and keep working during hard acceleration. But I'll test it again.
  • bryan200kbryan200k Posts: 64
    Bought my 2009 Civic LX-S just over a week ago. My first fill up was at 347 miles driven. 300 was Highway, 47 miles was City. Calculated MPG was 34.64 for first tank.
  • ras314ras314 Posts: 43
    I have a scan gauge and tried many times to determine the effect of the AC on mileage. Instantaneous mileage jumps around to much to make any comparison with AC on or off. Tried many times to run 10 miles over flat roads with no wind, still couldn't get conditions steady enough to see a noticeable difference with AC, Finally gave up and use the AC whenever I want. Maybe someone else has had better luck.

    My mileage has slowly increased as I put more miles on, now around 18000 and haven't see a tank fill in some time less than 45 mpg. 2007 civic with manual, probably around 95% or more highway and lots of 55 mph roads. At interstate speeds mileage will drop to 40 mpg and even less with headwinds.
  • kipkkipk Posts: 1,576
    >"I have a scan gauge and tried many times to determine the effect of the AC on mileage. Instantaneous mileage jumps around to much to make any comparison with AC on or off."

    Using the Scan Gauge also, in our 03 4wd Pilot.. On a flat road or even going up a slight grade, with cruise on, the instant mpg will hold reasonably steady enough to turn the AC button on for a few seconds, and off for a few seconds. Mileage when the AC is turned on will drop "instantly" by 2-3 mpg. Then turning it off will increase the mileage by the same amount.

    A 4 mile trip I take several times a week will typically return 2-3 mpg better with the AC off. That is starting with a cold engine. This spring, a 42 mile one way trip, I take often, yielded right at 27 mpg both directions. No AC. Cruise set at 58 mph for the X-Way portion.

    Now that the temps are in the 90s and AC is on most of the time, the mileage has dropped to more in the 24-25 mpg range, at the same speeds. . I can keep it more in the 25 mpg range by "re circulating" the inside air and turning the AC on and off by hand.

    Problem with Honda's Climate control is that if the AC is on, the compressor runs all the time. When the correct temperature is reached, the computer just adds heat to the system to maintain the correct temp. But the compressor continues to run.
    Without Climate Control, and the "AC ON" condition, the Compressor continues to run and it just gets colder and colder. The driver can add some heat or turn the AC off.

    Would seem to me to be better if the Compressor would turn on and off depending on whether or not more cooling is needed.

    Kip
  • ruking1ruking1 Posts: 14,488
    Actuall you guys with the scan gauge should try a different methodology.

    Normally the A/C system takes app 15 min to stabilize.

    Cycle the A/C ON. Put fan speed to #1. Regulate the coolness and leave it on.

    When you turn it on and off you are making the system work harder to get UP and attempt to stabilize. This of course consumes more energy than the above situation which already has the system UP and stabilized and you are just twiking the temp to suit.

    So anytime under that or cycling the system on and off will exact an mpg penality. Pass that, the system advances the timing slightly, takes little energy to stabilize the system and you should see pretty close to par for mpg.
  • kipkkipk Posts: 1,576
    I have tried it different ways, and the most efficient is using "Recirculate" as described above. When the "AC On" is displayed, the compressor runs continuously,

    My wifes CR-V doesn't have Climate Control, so when it gets too cold we have the option of adding heat with the temperature control knob or turning the AC OFF and stopping the compressor. The Pilots Climate control automatically adds the heat when needed to maintain a selected temperature, but the compressor continues to run as long as that AC ON is showing. It will do that also in the winter.

    The Pilot gets 2-3 mpg less when the Climate Control does all the controlling vs no AC at all. There is a 1-2 mpg difference when I use recirculate to cool the air and keep it inside the car.

    Whether or not it is worth the hassle to turn the compressor on and off by hand depends on the frame of mind at the time. Not suggesting that anyone should do any certain thing. Just giving the facts as the Scan Gauge presents them. It is possible that turning the compressor on and off is hard on the compressor clutch, and that may be the reason Honda chooses to leave it running constantly.

    Whatever their reason is, it cost me 2-3 MPG to run the air. So I just go with the flow and try to regain some of the mileage with driving techniques.

    Kip
  • ruking1ruking1 Posts: 14,488
    See, you have just done your fellow owners a favor.

    Also I have a newer technology A/C (VW & not temp/climate) and it also works as I have mentioned. Honda at some point needs to switch to the more fuel saving A/C. But then again there is little incentive with folks buying them as they do.
  • kipkkipk Posts: 1,576
    I was not in the room at the time but seems I heard on TV that VW is back with the Turbo Diesel, and it is getting super mileage. Seems they said 58 mpg. Is that possible?

    Kip
  • ruking1ruking1 Posts: 14,488
    ..."Seems they said 58 mpg. Is that possible?"...

    I realize this is off topic, but the answer is yes.

    I have done this across three states and a foreign country (had to count foreign country as I did a lot of stop and go driving and didn't buy fuel, as it was at least a $ more a gal than the US) , when three states (WA, OR, CA) had 5 highway patrol car wolf packs in full predatory mode (aka customer service) and the radar detector was going off so much, that it was just plain annoying. So I chose (03 VW Jetta TDI 5 spd manual) 75 mph with bursts to 80-85 and got 59 mpg (two fill ups) . NO TICKETS and I was surprised as anyone else, as I thought maybe... 55 mpg.

    Further off topic, on a trip to Vancouver BC (2300 miles) the 09 Jetta TDI (DSG) posted 43.5 mpg overall during a herky jerky break in mode. A/C blasting, 3 folks, truck STUFFED to the gills. The GPS when it was on, said the car didn't exceed 90 mph. ;) Torque is 115% greater than the below Civic. It also weighs 770#'s more.

    More on topic, a 04 Civic posted 38-42 mpg on a R/T to Portland OR. A/C blasting, 2 drivers, two small overnight bags.
  • kipkkipk Posts: 1,576
    That should get Honda, Toyota and the rest to the drawing boards. :)
  • dantzdantz Posts: 49
    thegraduate: Yes, you're right, the A/C does appear to cut out when the pedal is floored. So I guess my idea of measuring the time it takes to go from zero to 60 at max throttle with the A/C on vs off isn't going to work, as it will be off either way. I'll try to devise another way to measure the A/C's effect on performance.

    I hardly ever floor it, as I don't like to push the revs that high, and I guess that's why I never noticed the A/C doing that. However, during a "pretty brisk, but not quite floored" takeoff, which is closer to the way I drive when I need some extra power, the A/C appears to stay on.

    ras314, I'm sorry to hear that the scangauge doesn't display a steady enough instantaneous mileage reading to accurately measure the effects of A/C in a Civic. It's interesting that kipk has managed to do it in a Pilot. Perhaps the lighter, less powerful Civic is more at the mercy of small changes such as road grade, road condition, wind direction and intensity, etc. and this makes it harder to get a steady reading.

    Perhaps trying to compare the instantaneous mileage isn't the best way to do this. As I understand it, the scangauge can be set to measure the average mpg of various trips. I would think that driving at steady speed on a level highway and measuring the mpg during two short "trips" (for example, 3 miles each), beginning the first trip after the A/C has been on for awhile (following ruking1's advice) and doing the second short trip with the A/C off, should show the difference. According to the documentation, you can reset the "Current" trip while driving in order to accomplish this.

    Oh heck, I guess I'll have to buy a ScanGauge myself just to satisfy my curiosity.
  • motorcity6motorcity6 Posts: 427
    I don't own a Honda, but the Shell gas delivers the best mileage. Plus my Shell credit card gives a rebate on all items purchased at the Shell location including gas.

    The rebate is around 5%, so it is even cheaper than all the cut rate stations, and performance is better, and I use the midgrade every other tank..premium the balance. It's a 2006 Pontiac GPGT w/SC260hp V-6 and they recommend premium, but the performance difference between the mid & premium is minor..

    Almost bought the SI Civic, but after reading some of the posting on Edmunds concerning clutch and tranny issues under 15k miles with the dealers refusing to fix, blaming the failures on hot-rodding, enough to stop any further need for the SI.

    Looking for a fun-car, so I will get the Mustang GT w/track pkg..2nd car..Just drove a 2009 Mustang Bullitt from Venice, Fl to Detriot, flew low and averaged 18.5 mpgs

    The Pontiac gulps gas, but then again the a/c is on and sunroof open, with nets about 20.50 mpgs, w/Shell. Town driving..Florida living, hot and sunny..

    Good Luck with your Civics, drive slow for I need the gas..Owned 43 cars to date, no Asian cars, 2 German..The only 4 cylinder cars were 2 Porsches, farm tractor, and several outboards.
  • thegraduatethegraduate Posts: 9,731
    Don't worry about hurting the car; the car is engineered to handle revving well into the 6,000 RPM range. Actually, max horsepower isn't made until 6,300 RPM. So, if need-be, don't be afraid to mat the pedal. Nothing will happen (except some quicker acceleration!). :) If you don't need to accelerate that fast though, don't; save your gas! :shades:
  • kipkkipk Posts: 1,576
    >"ras314, I'm sorry to hear that the scangauge doesn't display a steady enough instantaneous mileage reading to accurately measure the effects of A/C in a Civic. It's interesting that kipk has managed to do it in a Pilot. Perhaps the lighter, less powerful Civic is more at the mercy of small changes such as road grade, road condition, wind direction and intensity, etc. and this makes it harder to get a steady reading. "

    Dantz,

    You may be right about the Pilot being a bit more "steady" as measured on the SG. Perhaps it is the Extra bulk and weight of the Pilot.

    The S. Gauge does fluctuate constantly though, even though the road appears to be somewhat stable in grade or lack of grade. Some of those fluctuations are more than expected. For example when a large "Box" truck or 18 wheeler passes from the opposite direction, on a 2 lane road, there may be a 3-5 mpg drop in mileage for a few seconds. When being passed from behind by one of them, there will be an increase in mileage.

    Something I just can't really understand is:

    Sometimes with the Cruise ON, and about to descend a long grade, with an equal appearing uphill grade to follow, I will reset the "Current Mileage" (Average mileage), so it can keep track of the average for that test. Then click on the "Instant" mileage. These numbers are not exact but somewhat representative.

    When decending the SC may show (Instant Mileage) from 56 mpg to 9999 (maxxed out) . When ascending the next grade, the SC may show 23 to 18. For those 2 grades the "Current Mileage" will show something like 27 mpg average for the short trip involving the 2 grades.

    I've double checked it by doing the same on the return trip on the same 2 grades and the result is similar It just boggles this old brain! :sick: .

    Kip
  • kipkkipk Posts: 1,576
    In 75 to 80 degree weather we will ride with all 4 windows cracked about 2 inches. If that keeps us comfortable fine. If it occasionally gets a bit hot due to sun or what ever, we will roll up the windows and do the recirculate AC ON and Off thing, IF every 10 to 15 minutes will keep the temperature about right.

    But those circumstances are rare or short lived. So if it gets too hot with the windows cracked, we will likely turn on the AC, with it set at 77 degrees, and let the Climate Control do it's thing. One less thing to be concerned about, and that is why we got it. Most or all the loss in mileage with the AC ON can be made up by dropping the speed a bit.

    Slightly lower speed and comfortable environment makes for a more pleasant trip.

    We tend to get all concerned about mileage and do things we think will get the best possible.

    Paying $0.20 more for premium fuel in a "Regular car, has no effect and not necessary unless traveling 80 mph in the mountains with a full load and towing a trailer in 100+ temperatures. (sarcasm)

    Paying 3-6 cents less for crappy gas doesn't really save anything and may actually cost more in the long run due to poor mileage, injector fouling, and so forth.

    Drafting an 18 wheeler will cost you more WHEN the stones, road dabree, and eventual crash mess up the front of your car.

    If we really think that traveling 80+ saves gas because we were on the road a shorter period of time, we may have inhaled too much exhaust from that 18 wheeler we were drafting. :shades:

    Bottom line is that the throttle and driving techniques have more to do with mileage than anything else. http://www.youtube.com/watch?v=kvrQQq9d2no
    Kip
  • ruking1ruking1 Posts: 14,488
    I do not think that Americans will be serious till they embrace or force the applicable regulatory agencies to implement alternative fuels (i.e., diesels) as a significant portion of the passenger vehicle fleet diesels, specifically 23% of the passenger vehicle fleet: being diesels. This will cut the demand for oil a MINIMUM of 23% !!! link title

    Some if it is based on the real life ratios of refinement of a barrel of oil RUG to PUG vs D2. Further downstream is the 20-40% better fuel mileage. So when you put those two together that is a serious lessenning of ... demand.

    Honda Civics for example are only a small segment of a minority called small cars (25%) . The rest or majority (75%) usually consume.... more. Now I am not advocating drivers wanting or needing say a size 14 shoe, needs to get into a size 5....

    Since there are no like model Civic comparison (US markets anyway), here is a (03 VW Jetta) like model comparison: 2.0, 25 mpg; 1.8T, 25 mpg; 1.9 TDI ,49 mpg. So assuming 12,000 to 15,000 miles per year (avg drivers') that is up to RUG, 600 gals, PUG, 600 gals vs D2, 306 gals or 49% savings.
  • backybacky Twin CitiesPosts: 18,628
    Heard a radio report today that said over 40 mph, it's more efficient to run the AC than leave windows open. Under 40, might save some gas to open the windows. But under 40 there's less airflow too. Today it's going to hit 90 and sunny and I have business attire on so I will have the AC on, regardless of speed.
  • dantzdantz Posts: 49
    I've never understood the point of those "A/C versus wide-open windows" comparisons.

    I've found that when driving at highway speeds in warm weather with the A/C off, it's a lot more enjoyable to keep the windows almost entirely closed. If I need some extra airflow then I just crack the right rear window an inch or so and turn up the fan. This produces plenty of ventilation, and there's far less wind noise than you would get from four wide-open windows.
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