Cold air vs warm air
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Cold air vs warm air - 7/27/2005 1:10:43 PM
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_Shifty_
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I can't figure out why cars get better mileage in summer than in winter...shouldn't cold air be denser and therefore better for combustion and mileage?
Anyone know?
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RE: Cold air vs warm air - 7/27/2005 1:18:34 PM
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redass02gt
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same air / fuel ratio, therefore more air = more gas
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RE: Cold air vs warm air - 7/27/2005 1:21:52 PM
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_Shifty_
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How are cars getting more air in summer?
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RE: Cold air vs warm air - 7/27/2005 1:48:21 PM
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redass02gt
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they get less air in summer, burning less fuel, therefore better economy.
in winter, they get more air, more fuel, less economy.
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RE: Cold air vs warm air - 7/27/2005 2:06:38 PM
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sandcracker21
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also in the winter one tends to run their heat, and that runs the alternater, wich in turn, WASTES GAS
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RE: Cold air vs warm air - 7/27/2005 2:22:01 PM
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99saleen351r
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quote:
ORIGINAL: sandcracker21
also in the winter one tends to run their heat, and that runs the alternater, wich in turn, WASTES GAS
Huh.......The alternater runs no matter what.If anything the AC would burn more gas when its running
< Message edited by 99saleen351r -- 7/27/2005 2:23:07 PM >
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RE: Cold air vs warm air - 7/27/2005 2:30:25 PM
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LightSmith
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An engine will be more efficient at a higher temperature up to the point of boiling the coolant. That or people don't add air to their tires as it gets colder.
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RE: Cold air vs warm air - 7/27/2005 2:35:25 PM
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99saleen351r
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quote:
ORIGINAL: LightSmith
An engine will be more efficient at a higher temperature up to the point of boiling the coolant. That or people don't add air to their tires as it gets colder.
Say what????????I might have to have my dog translate that for me
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99 Saleen 351r,Vortech S,4k, 565rwh 557.7trq. Msd,O/F X,power pipe,48 pnd inj,Forged motor,twisted wedge heads, fuel system,275 pulley,Snow methanol
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RE: Cold air vs warm air - 7/27/2005 2:42:55 PM
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LightSmith
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BA-WHOOF!! Whoof!
Uh, wait a minute. A hotter combustion chamber will burn the mixture more efficiently, a more complete burn. This is only true until coolant starts to boil, usually around the exhaust valve area first. Once detonation starts, your efficiency is gone.
You've gotten the tire part where the tire pressure drops as the temperature goes down, right?
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RE: Cold air vs warm air - 7/27/2005 2:59:39 PM
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_Shifty_
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I still don't get how an engine is getting less air in summer, and more in winter. How is that?
The heater thing is irrelevant, as stated above, alt runs all the time.
The hotter combustion chamber seems feasible, can anyone confirm that? Don't all engines get up to a hot temperature eventually, though, regardless of outside temp?
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RE: Cold air vs warm air - 7/27/2005 3:10:00 PM
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99saleen351r
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Air is more condesne when its cold there for getting more.And lightsmith I get what your saying just bustin them
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RE: Cold air vs warm air - 7/27/2005 3:39:42 PM
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redass02gt
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quote:
ORIGINAL: _Shifty_
I still don't get how an engine is getting less air in summer, and more in winter. How is that?
The heater thing is irrelevant, as stated above, alt runs all the time.
The hotter combustion chamber seems feasible, can anyone confirm that? Don't all engines get up to a hot temperature eventually, though, regardless of outside temp?
1. The difference in engine temp should be zero degrees if your **** is running well. Your engine warms up and stays at a stable temp. when warm, so winter and summer engine temp should be the same.
2. when the air is denser, there are more molecules of oxygen per 4.6 liters of air, assuming you have a 4.6L engine. When your engine takes in air, it will take in 4.6 liters of air per cycle. During winter, there are more molecules of oxygen in the 4.6 liters, because it's colder and denser. During summer, it is hotter, molecules are spread out more. During summer, when your engine takes 4.6 liters of air, there is less oxygen in those 4.6L of air, and you will burn less fuel. the air/fuel ratio should be the same, so more air requires more fuel. It's the same reason your tires will have a higher pressure when hot vs. when cold. Got it?
-Professor thermodynamics
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RE: Cold air vs warm air - 7/27/2005 3:41:09 PM
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redass02gt
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also, I'm not sure a more complete burn will matter enough to give you more power, but it will reduce emissions.
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RE: Cold air vs warm air - 7/27/2005 3:54:53 PM
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_Shifty_
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Okay, gotcha. So you're saying you get better mileage in summer, but better performance in cold weather?
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RE: Cold air vs warm air - 7/27/2005 3:57:58 PM
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redass02gt
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definitely correct. usually that's the case, better performance = crappier milage.
please notice I said usually.
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RE: Cold air vs warm air - 7/27/2005 4:03:11 PM
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_Shifty_
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Thanks. So the exceptions to that rule, then, would be mods that improve efficiency, I guess. Like a better flowing exhaust, that would improve both mileage and performance, right?
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RE: Cold air vs warm air - 7/27/2005 4:50:15 PM
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Derf00
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quote:
ORIGINAL: redass02gt
quote:
ORIGINAL: _Shifty_
I still don't get how an engine is getting less air in summer, and more in winter. How is that?
The heater thing is irrelevant, as stated above, alt runs all the time.
The hotter combustion chamber seems feasible, can anyone confirm that? Don't all engines get up to a hot temperature eventually, though, regardless of outside temp?
1. The difference in engine temp should be zero degrees if your **** is running well. Your engine warms up and stays at a stable temp. when warm, so winter and summer engine temp should be the same.
2. when the air is denser, there are more molecules of oxygen per 4.6 liters of air, assuming you have a 4.6L engine. When your engine takes in air, it will take in 4.6 liters of air per cycle. During winter, there are more molecules of oxygen in the 4.6 liters, because it's colder and denser. During summer, it is hotter, molecules are spread out more. During summer, when your engine takes 4.6 liters of air, there is less oxygen in those 4.6L of air, and you will burn less fuel. the air/fuel ratio should be the same, so more air requires more fuel. It's the same reason your tires will have a higher pressure when hot vs. when cold. Got it?
-Professor thermodynamics
Holy cra$! You answered something without being a smart ass..... j/k. Yep that's the answer!
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