In an emergency the crew argued.
But eventually they loaded the engines with one fuel rod each, then burned them dry in Stupid mode, which took six hours and accelerated Unexpected Finger by 200 mips (Miles Per Second.)
How did that feel?
200 miles per second is 320,000 m/s, and six hours is 21,600 seconds. So Finger accelerated at (320,000 m/s) / 21,600 s = 15m/s2, or 1.5 gravities.
1.5 gravities is more than Finger's normal, cruise acceleration. In fact it is 4.5 times more, so it consumed 4.5 times as much fuel. Earlier we calculated that Cruise thrust consumed 0.04 kg/s, so Stupid thrust consumed fuel of 4.5 × 0.04 kg/s = 0.18 kg/s.
Conversely, Stupid thrust consumed a fuel rod in six hours, so at Cruise thrust a rod would last 4.5 times longer, or 27 hours.