>>13760516oh boy.. ok.
>What determines how much gas a car consumes at a time (besides the engine/weight of course)?Basically, how many times your cylinders are firing. In other words, how many revolutions per minute (RPM).
Granted this is assuming it's the same engine. A 5L V8 will consume more gas than a 4cyl period.
Now beyond that there's outside factors that are going to determine your fuel efficiency, more on that below.
>For instance, will the car consume the same amount of gas running 2000 RPM in first gear as it will at 2000 RPM in fifth gear? Yes, but only in a vacuum. In real world application you'll be burning more fuel in 5th gear because you'll be going faster and there will be more air resistance and drag against your car.
>Or is it determined by how much I am pressing on the accelerator?Also yes, this is part of it. The more you open your throttle the more gas it will use, but that goes back to RPMs because those will increase when you hit the gas.
>Also, is the easiest way to find the "power band" just to throw it on a dynamo or is there a way to guestimate/calculate it?The easiest and most accurate way is to throw it on a dynamometer (dyno for short, not dynamo). This will give you a precise measurement, but if you don't have access to one you could get a feel for where it is, though less accurately. The power band is the area between peak torque and peak horsepower, in case that wasn't clear.
What is fairly easy to tell is when you're in the power band because of how the engine will feel.
When you ride a bike with gears, you couldn't start in high gear because you'd be pedaling and going no where, so you drop to a gear that is harder to pedal, but actually moves you. Now once you're going you move up a gear because as you get to certain speeds you hit a wall since you can only pedal so many times a minute (RPMs). It's the same in a car; it's fairly obvious when you need to shift up or down to keep it in the power band.
