Things that affect mileage
05-03-2007, 04:33 PM
#11
2nd Gear Member
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Join Date: Apr 2007
Location: The Hinterlands of Minne-snow-ta
Posts: 401
RE: Things that affect mileage
ORIGINAL: 07 Stang
Ya know, years ago we put the A/C theory to the test in my husband's then new Plymouth Champ. We were on the Interstate and road the first tank with the A/C on. Second tank with the A/C off and windows down.
We got better gas mileage by using the A/C because of less wind drag. Now if you are in the city with stop and go traffic, I would think using the A/C would cause you to get less gas mileage.
Ya know, years ago we put the A/C theory to the test in my husband's then new Plymouth Champ. We were on the Interstate and road the first tank with the A/C on. Second tank with the A/C off and windows down.
We got better gas mileage by using the A/C because of less wind drag. Now if you are in the city with stop and go traffic, I would think using the A/C would cause you to get less gas mileage.
05-03-2007, 04:47 PM
#12
MF Administrator
Join Date: May 2005
Location: South Carolina
Posts: 8,191
RE: Things that affect mileage
ORIGINAL: 07 Stang
Ya know, years ago we put the A/C theory to the test in my husband's then new Plymouth Champ. We were on the Interstate and road the first tank with the A/C on. Second tank with the A/C off and windows down.
We got better gas mileage by using the A/C because of less wind drag. Now if you are in the city with stop and go traffic, I would think using the A/C would cause you to get less gas mileage.
Ya know, years ago we put the A/C theory to the test in my husband's then new Plymouth Champ. We were on the Interstate and road the first tank with the A/C on. Second tank with the A/C off and windows down.
We got better gas mileage by using the A/C because of less wind drag. Now if you are in the city with stop and go traffic, I would think using the A/C would cause you to get less gas mileage.
05-03-2007, 10:39 PM
#13
3rd Gear Member
Join Date: Mar 2007
Location: Miami, FL
Posts: 704
RE: Things that affect mileage
ORIGINAL: 28HopUp
Mythbusters did a segment like that with the same results, but it seems to me that their test method was flawed. I can't remember why...
ORIGINAL: 07 Stang
Ya know, years ago we put the A/C theory to the test in my husband's then new Plymouth Champ. We were on the Interstate and road the first tank with the A/C on. Second tank with the A/C off and windows down.
We got better gas mileage by using the A/C because of less wind drag. Now if you are in the city with stop and go traffic, I would think using the A/C would cause you to get less gas mileage.
Ya know, years ago we put the A/C theory to the test in my husband's then new Plymouth Champ. We were on the Interstate and road the first tank with the A/C on. Second tank with the A/C off and windows down.
We got better gas mileage by using the A/C because of less wind drag. Now if you are in the city with stop and go traffic, I would think using the A/C would cause you to get less gas mileage.
05-04-2007, 02:09 AM
#14
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Join Date: May 2006
Location: Nutley NJ
Posts: 1,207
RE: Things that affect mileage
Thanks for the info. I always enjoy reading things like this.
As for the A/C issue...I feel that the gas milage is about the same, but throttle responce at low rpms suffers, so I always turn it off unless I really need it.
As for the mythbusters...I wish I could be on that show. They should have used the same car when doing their tests. Even though they used the same amout of gas in the same exact model car, we all know every car's performance and efficiency varry...
Heres some more scientific info I stole off the internet...
First, ethanol’s properties as a fuel. We need to get into a little bit of chemistry. Gasoline (and diesel) consists of multiple types of molecules consisting of hydrogen and carbon atoms in chains of different lengths. (Part of creating different fuels is the blending of these different types together.) For example, the structure of one gasoline molecule, Octane, is C8H18. When these hydrocarbon molecules burn (with oxygen), the result is heat and exhaust.
Unlike gasoline, ethanol contains oxygen in its structure. That oxygen doesn’t contribute directly to the net energy in the reaction -- but it does contribute to a more efficient burn. This structure allows ethanol to be used to oxygenate gas -- to put oxygen into the fuel to assist in the burn -- a primary use today. Because ethanol is not as carbon and hydrogen rich as petroleum-based fuels, it has a lower energy content for a given volume. Using ethanol as a fuel or just as an additive reduces fuel efficiency a bit simply because of the chemistry. Engine technology can compensate for some of that, and the fact that ethanol is renewable and free of the same GHG burden as gasoline makes it very attractive. So, no problem there. As a fuel, or even as an additive, ethanol is a fine alternative.
As for the A/C issue...I feel that the gas milage is about the same, but throttle responce at low rpms suffers, so I always turn it off unless I really need it.
As for the mythbusters...I wish I could be on that show. They should have used the same car when doing their tests. Even though they used the same amout of gas in the same exact model car, we all know every car's performance and efficiency varry...
Heres some more scientific info I stole off the internet...
First, ethanol’s properties as a fuel. We need to get into a little bit of chemistry. Gasoline (and diesel) consists of multiple types of molecules consisting of hydrogen and carbon atoms in chains of different lengths. (Part of creating different fuels is the blending of these different types together.) For example, the structure of one gasoline molecule, Octane, is C8H18. When these hydrocarbon molecules burn (with oxygen), the result is heat and exhaust.
Unlike gasoline, ethanol contains oxygen in its structure. That oxygen doesn’t contribute directly to the net energy in the reaction -- but it does contribute to a more efficient burn. This structure allows ethanol to be used to oxygenate gas -- to put oxygen into the fuel to assist in the burn -- a primary use today. Because ethanol is not as carbon and hydrogen rich as petroleum-based fuels, it has a lower energy content for a given volume. Using ethanol as a fuel or just as an additive reduces fuel efficiency a bit simply because of the chemistry. Engine technology can compensate for some of that, and the fact that ethanol is renewable and free of the same GHG burden as gasoline makes it very attractive. So, no problem there. As a fuel, or even as an additive, ethanol is a fine alternative.
05-04-2007, 09:49 AM
#15
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Join Date: Apr 2005
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Posts: 324
RE: Things that affect mileage
I notice ~ 1 mpg difference when I switch from the stock V6 16" rims/tires to the GT 17" take-offs. I switch back and forthevery so often for fall/winter weather or just to use up the 16's. Very repeatable results. I chalked it up to more rolling resistance on a wider tire?? I don't think the size difference is enough to cause this from what I remember they are very close OD.
05-04-2007, 10:00 AM
#16
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Join Date: Jan 2007
Location: Southeast Virginia
Posts: 6,409
RE: Things that affect mileage
ORIGINAL: Dean Martin
I notice ~ 1 mpg difference when I switch from the stock V6 16" rims/tires to the GT 17" take-offs. I switch back and forthevery so often for fall/winter weather or just to use up the 16's. Very repeatable results. I chalked it up to more rolling resistance on a wider tire?? I don't think the size difference is enough to cause this from what I remember they are very close OD.
I notice ~ 1 mpg difference when I switch from the stock V6 16" rims/tires to the GT 17" take-offs. I switch back and forthevery so often for fall/winter weather or just to use up the 16's. Very repeatable results. I chalked it up to more rolling resistance on a wider tire?? I don't think the size difference is enough to cause this from what I remember they are very close OD.
05-04-2007, 11:32 AM
#17
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Join Date: Sep 2006
Location: Orlando/Daytona Area, FL
Posts: 324
RE: Things that affect mileage
Low tire pressure will reduce mileage.
Heavier rotating parts will also reduce mileage. That is why ford does not make a 17" wheel standard on the V6, they need them to come with lighter 16s to get their CAFE up.
Heavier rotating parts will also reduce mileage. That is why ford does not make a 17" wheel standard on the V6, they need them to come with lighter 16s to get their CAFE up.
05-04-2007, 12:33 PM
#18
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Join Date: Apr 2007
Location: The Hinterlands of Minne-snow-ta
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RE: Things that affect mileage
I don't know what wheels and tires weigh, but do know there is a connection between tire/wheel size and mileage. One question I have is why a 17" wheel weighs more?
Like said, I really don't know -my logic is derived from the arm rests on my computer chair. But, it would seem to me that the difference in weight would be negligible from a 16"wheel and a 17" wheel. The rim itself would be the same (assuming the same width), as well as thehub. The only difference would be the length of the spokes, or the size of the spokes.
The outside circumference of the tire is the same - if it wasn't, we'd needto recalibrate the computer every time we switched wheels. If the outside circumference of the tire is the same, then the amount of tread is the same (assuming the same width). Therefore, the only difference is the size of the sidewall.
Rubber is heavy, aluminum is light, so I'd expect the actual weight of the tire/wheel combinationto be less, if anything - not more - when switch to a larger wheel size.
I think it's probably more a function of the tire design - treadpattern and width of the contact patch - that affects mileage. That's why tire pressure matters. Is this anywhere close to correct????
Like said, I really don't know -my logic is derived from the arm rests on my computer chair. But, it would seem to me that the difference in weight would be negligible from a 16"wheel and a 17" wheel. The rim itself would be the same (assuming the same width), as well as thehub. The only difference would be the length of the spokes, or the size of the spokes.
The outside circumference of the tire is the same - if it wasn't, we'd needto recalibrate the computer every time we switched wheels. If the outside circumference of the tire is the same, then the amount of tread is the same (assuming the same width). Therefore, the only difference is the size of the sidewall.
Rubber is heavy, aluminum is light, so I'd expect the actual weight of the tire/wheel combinationto be less, if anything - not more - when switch to a larger wheel size.
I think it's probably more a function of the tire design - treadpattern and width of the contact patch - that affects mileage. That's why tire pressure matters. Is this anywhere close to correct????
05-04-2007, 03:50 PM
#19
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Join Date: Apr 2005
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Posts: 324
RE: Things that affect mileage
ORIGINAL: 07 Stang
so are you saying you are getting less mpg with 17" rims? The 2007 V6 Mustangs with the Pony Package comes with 17" rims.
ORIGINAL: Dean Martin
I notice ~ 1 mpg difference when I switch from the stock V6 16" rims/tires to the GT 17" take-offs. I switch back and forthevery so often for fall/winter weather or just to use up the 16's. Very repeatable results. I chalked it up to more rolling resistance on a wider tire?? I don't think the size difference is enough to cause this from what I remember they are very close OD.
I notice ~ 1 mpg difference when I switch from the stock V6 16" rims/tires to the GT 17" take-offs. I switch back and forthevery so often for fall/winter weather or just to use up the 16's. Very repeatable results. I chalked it up to more rolling resistance on a wider tire?? I don't think the size difference is enough to cause this from what I remember they are very close OD.
05-04-2007, 09:07 PM
#20
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Join Date: Jun 2006
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Posts: 211
RE: Things that affect mileage
I went from Stock 17' bullits to 18x9 after market Bullits. The stock rims with tires,are 47.5 lbs. And my new ones are 54 lbs with tires.So 7.5 lbs more per wheel, 30lbs total more per car.