Michael, I was entering different C.I. values by trial and error. I entered a value 0f 110 on one flight with a Cruise Alt of 220 and 45% in the Left and Right tank and got the Fuel Warning. I don't do long-haul flights. All flight I do are short-haul flights from 1-3 hrs "Block to Block". btw, I was mistaken about entering 0 in the C.I. box. Entering 0 in the box will not trigger a Insufficient Fuel Warning. This morning I created a flight from KCLT-KMCO with 29000 lbs in the L&R tanks with a Res of 13000 lbs and entered a C.I. of 80 at a Cruise Alt of 310 and did not get the warning. Hope this makes sense.