Oh... My... God...

aperson · Post by **aperson** » Mon Jun 16, 2008 12:46 am

This can't be real.
Using warm air to increase MPG? Come on. total and utter BS. Fun to read for a bit, but don't read for too long other wise you're head will hurt.

http://hypermiling.com/phpBB3/viewtopic.php?f=2&t=64

Nutmeg · Post by **Nutmeg** » Mon Jun 16, 2008 12:58 am

mikehelms wrote:
heathenbrewing wrote:
mikehelms wrote:
Cold dense air is for increasing horsepower, not MPG. Warm air would do just the opposite, reduce power but increase MPGs.

If power is increased, then it would take less fuel (and air) in total to keep the car moving at the same speed, no?

Cheers,
-- Mike

I think increasing power would require more fuel, not less.

My understanding is that cold air has more O2 by volume as compared to warm air, so you can stuff more fuel into the cylinder while maintaining the proper air/fuel ratio. Thats one reason why the go-fast people like it.

The warmer air from your engine compartment is better for fuel economy because is has less oxygen molecules than a cold air charge. This increases your fuel efficency, but decreases your horsepower.

Cold air = more power, and you use less of the accelerator pedal, which is basically the throttle control. Less use of the pedal = (basically) closed throttle plate. Closed throttle plate means a restriction of the "air pump, or intake" - you have a pumping loss in that air is not getting in efficiently.

Warm air = less power, and you use more of the accelerator pedal, which is basically a throttle control. More use of the pedal = a more open throttle plate. Open throttle plate means there is less of a blockage thats letting the air in, reducing the pumping loss.

At wide open throttle, you have (basically) no pumping loss at the throttle plate. so warm air intakes wont do anything here. But unless 55mph makes you have to floor it to keep going 55, a warm intake will do something. That something depends on the vehicle.

Prost!,
Keith

This person knows nothing. Cold air does not have more "O2" by volume. Temperature directly relates to the speed at which the molecules are moving. Imagine you're heating up water over a stove in a closed container. The water becomes hotter, but you don't lose any water molecules. If you turn the stove off, it becomes cold, but water molecules don't magically just appear.

Some people are stupid. Screw the MPG issue.

ZeroChad · Post by **ZeroChad** » Mon Jun 16, 2008 12:59 am

I did try a K&N but saw no increase in mileage, so I went back to paper filters since they filter better than the K&Ns do.

Lol nice. My buddy has a 1gn xB. He has a scangauge II hooked up and removed the snorkel-uberestrictive intake pipe and he said the intake air temp jumped over 100F. You can have all sorts of scientific-chemistry debates about it, but it doesn't sound good for the engine to me.

Nutmeg: P*V=n*R*T

Post by **racer12306** » Mon Jun 16, 2008 9:20 am

ZeroChad wrote:Nutmeg: P*V=n*R*T

AHHHHHHHHHH

Colder air does have more oxygen per volume, that is why cars make more power in cold air.

I'm not going to read all that because I think hypermiling is stupid, so my head will hurt. But when you make more power you are taking load off the engine at given speeds. Also more power is produced by burning the fuel more effeciently and thus getting the same amount of power as before but with less fuel.

esteinmaier · Post by **esteinmaier** » Mon Jun 16, 2008 10:09 am

Nutmeg wrote:
mikehelms wrote:
heathenbrewing wrote:
mikehelms wrote:
Cold dense air is for increasing horsepower, not MPG. Warm air would do just the opposite, reduce power but increase MPGs.

If power is increased, then it would take less fuel (and air) in total to keep the car moving at the same speed, no?

Cheers,
-- Mike

I think increasing power would require more fuel, not less.

My understanding is that cold air has more O2 by volume as compared to warm air, so you can stuff more fuel into the cylinder while maintaining the proper air/fuel ratio. Thats one reason why the go-fast people like it.

The warmer air from your engine compartment is better for fuel economy because is has less oxygen molecules than a cold air charge. This increases your fuel efficency, but decreases your horsepower.

Cold air = more power, and you use less of the accelerator pedal, which is basically the throttle control. Less use of the pedal = (basically) closed throttle plate. Closed throttle plate means a restriction of the "air pump, or intake" - you have a pumping loss in that air is not getting in efficiently.

Warm air = less power, and you use more of the accelerator pedal, which is basically a throttle control. More use of the pedal = a more open throttle plate. Open throttle plate means there is less of a blockage thats letting the air in, reducing the pumping loss.

At wide open throttle, you have (basically) no pumping loss at the throttle plate. so warm air intakes wont do anything here. But unless 55mph makes you have to floor it to keep going 55, a warm intake will do something. That something depends on the vehicle.

Prost!,
Keith
This person knows nothing. Cold air does not have more "O2" by volume. Temperature directly relates to the speed at which the molecules are moving. Imagine you're heating up water over a stove in a closed container. The water becomes hotter, but you don't lose any water molecules. If you turn the stove off, it becomes cold, but water molecules don't magically just appear.

Some people are stupid. Screw the MPG issue.

Um, cold air does have more oxygen per given volumetric unit than warmer air. A gas expands and contracts exponentially compared to a liquid.

That being said, it still takes X horsepower to maintain Y MPH at a given rate of aerodynamic drag. So regardless of whether it takes more or less air to maintain a full burn, it will still require the same amount of fuel. That's why leaning out cruise only goes so far to increase MPG. As you inject less fuel, you also subtract power accordingly.

If you want better gas mileage, you need to decrease the amount of power required to drive. Reducing weight will improve accel MPG, and reducing drag will improve cruise. That is why a metro gets huge MPG numbers. Not the small engine.

Nutmeg · Post by **Nutmeg** » Mon Jun 16, 2008 10:29 am

Hrm, well I must be largely mistaken.

ZeroChad: I completely forgot about the ideal gas equation. Of course, as you increase volume to an thermal equilibrium, the temperature has to drop. Or the pressure. And vice versa.

I forgot you can't just decrease temperature without affecting the pressure or volume. Thanks for straightening that out.

bombtrack07 · Post by **bombtrack07** » Mon Jun 16, 2008 12:42 pm

if you want more MPG then buy a freaking bike! the guys on that website fell out of the stupid tree and hit every branch on the way down.

glasswars · Post by **glasswars** » Mon Jun 16, 2008 4:29 pm

this thread makes my head explode

kc2005ptgt · Post by **kc2005ptgt** » Mon Jun 16, 2008 5:39 pm

BOOM!

heyitsstock · Post by **heyitsstock** » Mon Jun 16, 2008 5:42 pm

...Thusly if we use the Fluxcapacitor then we can congregate an accurate rate of time travel...

also note that
dog + pickles = mickey mouse's daughter

kc2005ptgt · Post by **kc2005ptgt** » Mon Jun 16, 2008 5:43 pm

E=Eeeeeeeee!!!
M=Mmmmmm!!!
C=See?
2=[]

MoxHair · Post by **MoxHair** » Mon Jun 16, 2008 7:06 pm

racer12306 wrote:
ZeroChad wrote:Nutmeg: P*V=n*R*T
I think hypermiling is stupid

Yep, thats says it all..

I need not go any further with this thread.

Post by **occasional demons** » Mon Jun 16, 2008 10:16 pm

They hooked hot air to this monkey with a big blunt attached to the other end.

http://photobucket.com/player.swf?file= ... &os=1&ap=1