It would seem to me that the most important thing while accelerating is not instant fuel mileage, but rather best efficiency.
Internal combustion engines get better fuel efficiencies as you lay your foot into it, at least up until the engine starts to run rich. And lower than max torque is best for best fuel mileage.
In my diesel I just floor it and keep RPMs as low as possible, 1,000RPMs and up. Max injection is still lean of stoichiometric so I don't have worry about that.
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