How is it more fuel efficient to shift at 2000rpm?

Question

doesnt shifting too early over work the engine? making it less fuel efficient?

Answer 1

Depends on the engine, the load at that time, lots of factors. If, after you upshift the motor seems strained and lugging, then you upshifted too early.

I usually upshift at 3000, which drops the RPM down to about 2000.