quote:

Originally posted by failsafe I totally disagree that 1, 4, 5 are bullshit. Obviously you haven't taken much areodynamic theory. Parasite drag is exponently related to velocity. So with that being a fact #1 is bang on the money in theory. The engine drives an acessory drive which the AC is on. If the AC is pumping full bore it puts a load on the acessory drive which in turn makes the engine work harder for the same speed. The drag caused by the open window is a definate factor. Don't you hear the buffet noise when you have a window open? Air is moving into the vehicle and increasing and decreasing the pressure inside causing the buffet noise. with the window slightly open you're dealing with vacuum drag. Anyway, a basic understanding of aerodynamics would clear this all up for you. As for the percentage of fuel consumption saved, I can't argue for. The theory is bang on though.

yeah, but they're so minor that its bullshit.

for example, window drag is such a myth that no one ever proved that it does use more gaz for cars (not supercars going at 300km).

AC uses more engine power, but its nowhere near 20%, my ac is on all the time and I don't see any noticeable change with the milage.

finally, when I look at my engine's rev, I see for 100kmh @ ~2000rpm and 120kmh @ ~2400rpm. Looks like my engine is working 20% harder, but also drives 20% faster so it equals itself. But I agree that it varies greatly from car to car (4v vs 6v vs 8v).

And try to explain this, with a full tank i drive around for 400km half highway, half city. And when I do Mtl-TO (550km), I use a full tank driving at 150-160kmh with full ac the whole time.

If infact driving faster used that much more gaz plus AC use, then I would've barely gotten 400km out a full tank even though its only a highway drive.

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vacuum drag isn't a myth, quite honestly it's scientific fact. Your RPM indications for different speeds would have to be more accurate then that. The internal combustion engine isn't efficent like that. A 10% increase in throttle does not EVER give you a 10% increase in speed. There's so many factors that rob the efficency. So saying that your car has a directly proportionate speed vs RPM ratio is absurd.

quote:

Originally posted by malek And try to explain this, with a full tank i drive around for 400km half highway, half city. And when I do Mtl-TO (550km), I use a full tank driving at 150-160kmh with full ac the whole time. If infact driving faster used that much more gaz plus AC use, then I would've barely gotten 400km out a full tank even though its only a highway drive.

i believe the factor in that one is the constant breaking and accelerating in the city, whereas in the highway you usually maintain a constant speed

the use of cruise control actually increases fuel consumption, if i remember correctly. cant quite remember what the effects are but the engine has to put more energy into maintaining the set speed.

basically, while all these little tricks and tips do save you some gas, you're gonna spend it anyways, and i dont think the savings are really that significant. the best is to take transit, walk or bike

quote:

Originally posted by malek #1, #4 and #5 are bullshit.

YOUR bullshit! lol

quote:

Originally posted by Playa24_7 YOUR bullshit! lol

LMAO Dan....too much

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quote:

Originally posted by malek #1, #4 and #5 are bullshit.

No it is not, as mentioned above....

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Volodymyr

quote:

Originally posted by malek yeah, but they're so minor that its bullshit. for example, window drag is such a myth that no one ever proved that it does use more gaz for cars (not supercars going at 300km). AC uses more engine power, but its nowhere near 20%, my ac is on all the time and I don't see any noticeable change with the milage. finally, when I look at my engine's rev, I see for 100kmh @ ~2000rpm and 120kmh @ ~2400rpm. Looks like my engine is working 20% harder, but also drives 20% faster so it equals itself. But I agree that it varies greatly from car to car (4v vs 6v vs 8v). And try to explain this, with a full tank i drive around for 400km half highway, half city. And when I do Mtl-TO (550km), I use a full tank driving at 150-160kmh with full ac the whole time. If infact driving faster used that much more gaz plus AC use, then I would've barely gotten 400km out a full tank even though its only a highway drive.

I see this possible if you have V6 over 3.8 or V8 over 4L engine. With 4 cylinder engine there is no way you will use same amount of gas driving so fast and having A/C on. I have 4 cylinders(150 hp) and there is definite horse pawer decrease when my A/C is on. You can even feel it when driving on cruise, put A/C on and suddenly you feel this "drag". That sucks about 10 - 20 % of gas.

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Volodymyr

quote:

Originally posted by malek AC uses more engine power, but its nowhere near 20%, my ac is on all the time and I don't see any noticeable change with the milage. And try to explain this, with a full tank i drive around for 400km half highway, half city. And when I do Mtl-TO (550km), I use a full tank driving at 150-160kmh with full ac the whole time. If infact driving faster used that much more gaz plus AC use, then I would've barely gotten 400km out a full tank even though its only a highway drive.

I drive a little 4 banger 1994 Toyota, and when I use the AC, I can really tell how hard my car is working to keep it cold inside. I even showed my sister how it actually changes the gas levels when it's on and off, depending on how fast the car is moving... We were going up a hill once with AC on, turned it off and we got this huge burst of power from the engine, and the gas metre even went up a bit.

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quote:

Originally posted by awishabear We were going up a hill once with AC on, turned it off and we got this huge burst of power from the engine, and the gas metre even went up a bit.

That's because you were going downhill.

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Failed at becoming a god...

quote:

Originally posted by OrZonE That's because you were going downhill.

LOL no this was when we were still going up... it was a really steep hill

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"Words are for those with promises to keep." -- W.H. Auden, Their Lonely Betters
"Ideology signifies the imaginary ways in which men experience the real world." -- Terry Eagleton (critic)

I think everybody is right. It's what we have heard from the Media that makes us say what we say. I've heard all the above arguments. Gas prices suck and they will continue to suck. It's times like these that we have to come together and stand as one. Make Love Not War.... LOL Funny Haha

#32 - Lay off the Breakfast Burieto's

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