the point is, that it takes far less energy to keep up a certain speed than you make at say 70mph, thus, you shift up, so that you make less power, but due to mechanical advantage keep the same speed... why do you have a hard time with this issue? XD
Look, you want proof? Buy a full tank of gas, and redline it EVERYWHERE until it burns away, then buy another one, and drive it as low an rpm as you possibly can, and you'll find that you are sorely mistaken.
Yes, an engine is generally most efficient at its torque peak, thus it can take in the most fuel and air as it can burn. Notice: as much AIR AND FUEL AS IT CAN BURN.
Bam.
You burn far more fuel at higher rpms than you do at lower because despite the increase in engine efficiency, that simply allows it to take in even more fuel and put out even more power. Because of the mechanical advantage of higher gears, and the fact that to coast at a constant speed you simply need to equalize torque output (acceleration) vs. wind resistance and such (deceleration), often that power is entirely wasted in a lower gear, because the mechanical advantage, the actual total efficiency of the drivetrain, is far lower.
Higher gears trade torque for mechanical advantage. Simple f**king physics
oh, and....
At 3500 rpm the throttle plate will be closed more than at 2500rpm.
Nope.... not at all. No way. The throttle plate (when in the proper position for giving exactly the right air flow required by the engine to maintain a speed) will be more open at 3500 rpm than at 2500 rpm, regardless of what gear you're in, because the air requirements of 3500 rpm are higher than at 2500 rpm.
Since your doing more combustion cycles per second it will take less fuel(in turn less air) per combustion cycle to make the same amount of power you were at 2500rpm.
Do you realize exactly what you're saying there? Alright, an engine has a certain amount of displacement. After a combustion cycle, that displacement creates a vacuum in the cylinder, which pulls in a certain amount of air, which requires a certain amount of fuel. The amount of air pulled in per cycle does not change, by the nature of pressure equalization. An engine, when the intake valves are opened, pulls in enough air to attain atmospheric pressure (ever notice how cars don't perform as well at high altitudes? this is why they put turbochargers on airplane engines, because the pressure up there is so low that air needs to be forced into the cylinders in order to attain high enough power to maintain flight). After a combustion cycle, the gasses inside the cylinder are at very high pressure, due to the cooling of the exploded gasses, and shoot out of the cylinder, then the piston starts pulling down, creating a vacuum again, ad nauseum.
Now, it stands to reason that if every combustion cycle pulls in pretty much the same amount of air (it all really depends on the way a cam is ground, so it's not necessarily a complete pull of air, but for our purposes, let's pretend), and that air is mixed with enough fuel to keep the combustion at, say, stoichiometric levels, then at higher rpms, the amount of air displaced and fuel used is greater than at lower rpms.
Jeez, this shouldn't even be an argument. This is high school physics.... I should know.... I'm in high school (helps that my dad's a physicist though
![Razz :P](./images/smilies/icon_razz.gif)
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I just gave strong, hard reason on why Gro and I are right.
Just stop trying to argue it.
Physics man... Physics.