What wastes more gas?
#4
05-05-2005, 01:33 PM
#6
05-05-2005, 04:34 PM
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Mythbusters did a test on this exact issue. Funny enough, they ended up using identical Expiditions with the 5.4 2 valve. The did the tests with two different people going around the track in each vehicle at first. The gas mileage was the same.
Then they tested with windows down and one with windows up ac on. The windows down vehicle won, but by a small margin. It was only something like .5 MPG better or something. It was enough to measure, but that's it.
Then they tested with windows down and one with windows up ac on. The windows down vehicle won, but by a small margin. It was only something like .5 MPG better or something. It was enough to measure, but that's it.
#7
05-05-2005, 05:47 PM
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#8
05-05-2005, 07:08 PM
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Sure the show is for entertainment, but that doesn't make the results false. In any case, I doubt the difference is large enough make going against your preference worth it. I myself prefer windows down, wind blowing across my face. In fact, I use the A/C so rarely that I've never charged the A/C in any vehicle I've ever owned.
Last edited by AegisSailor; 05-05-2005 at 07:12 PM.
#10
05-06-2005, 05:59 AM
#11
05-06-2005, 09:20 AM
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Hey, I'm just attempting to repeat what the Mythbusters found. Watching the show, I couldn't find any flaw in their logic. Not that I couldn't be flawed in my thinking.
The other thing they did was drain the tanks as much as humanly possible. Then using the same gas trolley, they put in exactly 5 gallons. The both went around the track using cruise. I think it was at 55 or 60, can't remember for sure. But they went around the track at the same speed opposite of each other. It was an oval track so wind shoudl be negated. But the one without AC running went something like 20 laps further. It was something like 15 miles or so. After all that, it equated to less than a MPG difference. While measurable, not huge.
On a pesonal note, I try to not use the AC unless it's really necessary. But I still like to be comfortable. My mileage results on my 2003 Supercrew are similar to what the Mythbusters found.
The other thing they did was drain the tanks as much as humanly possible. Then using the same gas trolley, they put in exactly 5 gallons. The both went around the track using cruise. I think it was at 55 or 60, can't remember for sure. But they went around the track at the same speed opposite of each other. It was an oval track so wind shoudl be negated. But the one without AC running went something like 20 laps further. It was something like 15 miles or so. After all that, it equated to less than a MPG difference. While measurable, not huge.
On a pesonal note, I try to not use the AC unless it's really necessary. But I still like to be comfortable. My mileage results on my 2003 Supercrew are similar to what the Mythbusters found.
#12
05-06-2005, 09:52 AM
#13
05-06-2005, 10:27 AM
Lets keep the debate going;
As long as we are going to bring in other sites;
http://www.straightdope.com/classics/a2_393.html
http://www.ehow.com/tips_2629.html
http://www.wkbt.com/global/story.asp...Type=Printable
http://money.cnn.com/2002/12/23/pf/autos/save_gas
These back up my information.
Bet you can find some that don't...
Every time I have tested it, with modern cars/trucks, the closed windows won.
Every 4 door I have had, modern body, couldn't be driven on the freeway with the rear windows down. Shaking and air thumping. You could drive with the front windows down, but since they discontinued wind-wings, they have never cooled very well that way.
EPA says tests have shown that at true freeway speeds, A/C on gets better mileage on everything EPA has tested.
Of course, that’s the EPA, the ‘your results may vary’ people.
The whole thing is kinda academic around here, as over 90, running the window down doesn’t actually help much. On Hot days it's even worse.
Finally, Apples to Oranges again.
If you put the A/C on, and use the heat blend to cool your interior, and never release the A/C then you are NOT trying for good mileage.
Lowering and raising the windows a dozen times while driving around town, shopping, will use enough electricity that the gas used to recharge the battery will more than eat your gains, if any.
If you are hand cranking both sides, well, sorry, but you MIGHT be saving miles, but I don’t want to be working at the desk next to you…
You can save more gas by putting up a front window shade when you stop.
Correct way to drive for mileage is to use the A/C only when you need it, and release the compressor when you don't, for taking off, or for passing. Use the compressor switch that they include just for that.
Incorrect way is to set the temp with the temp setting, The truck keeps the A/C cycling, and blends warm air with the cold to get your temperature
Check the temperatures that they 'test' at.
Windows down driving around here, cool day, inside temps about 85 with the windows down. To keep it 85 with the A/C on, using it properly, you would only be cycling the compressor about 10 percent of the time.
Think a little on these tests. If mythbusters had actually been trying to prove something, rather than 'entertaining' wouldn't they have done the EPA loop?
EPA says use the A/C.
Or better still, driven the truck at the average freeway speed, 72 mph in the city, 77 mph in the country?
Or used an aerodynamic vehicle, rather than something shaped a lot like a motorized brick... Sorry to my friends with the Expy…
In these ‘tests’ you either use the A/C full on, no matter what the temp, or conditions, or you run the windows down and they don’t test if it’s hot. Say 113 in the shade.
Most of the time, I have the blower on 2, and the A/C off, windows up. When it gets a little warm, I cycle the compressor till the truck is cool, then release the compressor. Five minutes later I may do it again.
It is easy, and certainly no harder than rolling your window up or down a little depending on comfort.
Oh well, why don't some of you try it, both ways. If you have an Info panel, or a Scangauge, or vacuum gauge, it's an easy test. Get it up to your favorite freeway speed, and put it on cruise. Check your instant mileage, then run the windows down, and release the compressor. I have done this test, and know what happened. Someone else try it.
Chris
As long as we are going to bring in other sites;
http://www.straightdope.com/classics/a2_393.html
http://www.ehow.com/tips_2629.html
http://www.wkbt.com/global/story.asp...Type=Printable
http://money.cnn.com/2002/12/23/pf/autos/save_gas
These back up my information.
Bet you can find some that don't...
Every time I have tested it, with modern cars/trucks, the closed windows won.
Every 4 door I have had, modern body, couldn't be driven on the freeway with the rear windows down. Shaking and air thumping. You could drive with the front windows down, but since they discontinued wind-wings, they have never cooled very well that way.
EPA says tests have shown that at true freeway speeds, A/C on gets better mileage on everything EPA has tested.
Of course, that’s the EPA, the ‘your results may vary’ people.
The whole thing is kinda academic around here, as over 90, running the window down doesn’t actually help much. On Hot days it's even worse.
Finally, Apples to Oranges again.
If you put the A/C on, and use the heat blend to cool your interior, and never release the A/C then you are NOT trying for good mileage.
Lowering and raising the windows a dozen times while driving around town, shopping, will use enough electricity that the gas used to recharge the battery will more than eat your gains, if any.
If you are hand cranking both sides, well, sorry, but you MIGHT be saving miles, but I don’t want to be working at the desk next to you…
You can save more gas by putting up a front window shade when you stop.
Correct way to drive for mileage is to use the A/C only when you need it, and release the compressor when you don't, for taking off, or for passing. Use the compressor switch that they include just for that.
Incorrect way is to set the temp with the temp setting, The truck keeps the A/C cycling, and blends warm air with the cold to get your temperature
Check the temperatures that they 'test' at.
Windows down driving around here, cool day, inside temps about 85 with the windows down. To keep it 85 with the A/C on, using it properly, you would only be cycling the compressor about 10 percent of the time.
Think a little on these tests. If mythbusters had actually been trying to prove something, rather than 'entertaining' wouldn't they have done the EPA loop?
EPA says use the A/C.
Or better still, driven the truck at the average freeway speed, 72 mph in the city, 77 mph in the country?
Or used an aerodynamic vehicle, rather than something shaped a lot like a motorized brick... Sorry to my friends with the Expy…
In these ‘tests’ you either use the A/C full on, no matter what the temp, or conditions, or you run the windows down and they don’t test if it’s hot. Say 113 in the shade.
Most of the time, I have the blower on 2, and the A/C off, windows up. When it gets a little warm, I cycle the compressor till the truck is cool, then release the compressor. Five minutes later I may do it again.
It is easy, and certainly no harder than rolling your window up or down a little depending on comfort.
Oh well, why don't some of you try it, both ways. If you have an Info panel, or a Scangauge, or vacuum gauge, it's an easy test. Get it up to your favorite freeway speed, and put it on cruise. Check your instant mileage, then run the windows down, and release the compressor. I have done this test, and know what happened. Someone else try it.
Chris
#14
05-06-2005, 11:08 AM
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Guys, I hate to break this to you, but you have a 300 HP V-8 pickup that weighs 5000+ lbs and stands nearly 7 feet tall.....if We truely cared about fuel economy at all we would not have this vehicle. (Maybe you have the 4.6 L but I have the 5.4 :-) The difference between windows and AC is miniscule in a vehicle with the frontal area this beast has---you can't increase the drag much beyond what it already is cause it is so damn big just by opening the windows. Look at the rearview mirrors....you want to really improve fuel economy, get rid of em or make em smaller and blend them into the body more...those suckers produce some real, tangible parasite drag.
Windows up and AC on would be more fuel efficient in something aerodynamic, but in a full sized truck like this its like debating whether falling off the 100th floor of a building is worse than jumping of the 80th floor or getting pused off the 50th floor..the end result is the same.
As far as cycling the compressor goes, look at the RPM difference with the cruise control on level ground and highway speed---barely perceptible. On a smaller engine it would take more fuel to keep the engine speed adequate to maintain constant speed with the compressor turning, but on something this big you don't notice it. Kind of like putting 500 lbs in the back of a Geo Metro vs putting 500 lbs in the back of an F-150.....you notice it a lot more in the tiny car with a tiny engine.
Windows up and AC on would be more fuel efficient in something aerodynamic, but in a full sized truck like this its like debating whether falling off the 100th floor of a building is worse than jumping of the 80th floor or getting pused off the 50th floor..the end result is the same.
As far as cycling the compressor goes, look at the RPM difference with the cruise control on level ground and highway speed---barely perceptible. On a smaller engine it would take more fuel to keep the engine speed adequate to maintain constant speed with the compressor turning, but on something this big you don't notice it. Kind of like putting 500 lbs in the back of a Geo Metro vs putting 500 lbs in the back of an F-150.....you notice it a lot more in the tiny car with a tiny engine.
Last edited by EMB135Driver; 05-06-2005 at 11:11 AM.
#15
05-06-2005, 11:26 AM
I've owned a flock of Metro's and while you do 'notice' the A/C more than on a truck, even the 3 cyl Suzuki carries the new compressors quite well. Just remarking that because the Suzuki gets a heck of a lot of bad press, mostly from people that don't drive them.
If you want gas mileage, get a stick Metro, the non-3 valve motor. 50+ is normal, on the freeway, and 30+ around town is nothing.
The auto trans costs it about 30-40 percent of the mileage.... 30 highway and 26 city with the auto. So get the stick. And for parking, just put a ramp up into the bed of your F-150, and store them both in the same parking place...
Sorry had to do the small joke.
On the slightly serious side, the hybrids get rotten mileage compared to a stock, stick Suzuki. If someone wants great mileage and no 'capital investment' just get a low mileage used Stick Metro/Swift, etc. Get used to your elbows hitting the doors, but they have head room like the F-150, and plenty of leg room. They are also narrow enough that you can 'wedge' them into a two car garage next to your big Supercrew, with plenty of room.
Chris
If you want gas mileage, get a stick Metro, the non-3 valve motor. 50+ is normal, on the freeway, and 30+ around town is nothing.
The auto trans costs it about 30-40 percent of the mileage.... 30 highway and 26 city with the auto. So get the stick. And for parking, just put a ramp up into the bed of your F-150, and store them both in the same parking place...
Sorry had to do the small joke.
On the slightly serious side, the hybrids get rotten mileage compared to a stock, stick Suzuki. If someone wants great mileage and no 'capital investment' just get a low mileage used Stick Metro/Swift, etc. Get used to your elbows hitting the doors, but they have head room like the F-150, and plenty of leg room. They are also narrow enough that you can 'wedge' them into a two car garage next to your big Supercrew, with plenty of room.
Chris