Try a block of 10T/hr so as you can make a quick decision, after glancing at the Fuel Totalizer on the FE's panel, on where to divert then call for the burn rate at the 3 eng crz (long range) FL from the performance tables which should be the your company's AOM which is available in the aircraft library
Note: the burn with 4 at optimum crz FL is pretty much the same as the burn with 3 at 3 eng alt capability - lower crz level = higher burn, higher EPR = higher burn.
Some may have forgotten what CRM in a 3 man aeroplane is really like..............hhmmmmmm heaven
Or it may be the case that most have raced up the career ladder (C152 instr to Hvy Jet) so fast they skipped performance and experience.
