Gearing is very important as well thus why newer AT have 8 speeds or more to stay in that sweet spot which is usually around 40% of redline, that is just an estimate. Even if you have low RPM's, that doesn't mean that the pulse-width on the fuel injectors isn't opened longer. That is precisely what happens. Increase the pulse-width, injector stays open longer and uses more fuel. Regardless of gearing, you would hit a wall around 60mph. If this weren't the case, then people would be getting crazy amounts of MPG going at very high rates of speed. If drag had no effect, then a car going 100mph at 2,000rpms would get amazing MPG's, as we know, that isn't the case thanks to drag. What a drag!:x
- Aaron