[elhigh]

Find a Brake Specific Fuel Consumption map for your engine. It will show you how much fuel you're burning for the engine's load and rev range.

Somewhere on that map you'll see where the isobars probably make a zone of lowest consumption per unit of power at a certain loading and speed. Aim to do all your accelerating in that zone of load and speed.

Barring being able to find the BSFC map, aim to do all your accelerating in and around the engine's torque peak, which for you is at 1900 rpm. It'll be in the ballpark, even knowing that the torque peak assumes WOT for the test. Gear in, let out the clutch, foot flat to just past the torque peak rev point, shift. Repeat as necessary until you are at your desired speed.