Originally Posted by
Bosi72
Typical sales brochures assume ISA conditions and a light airframe; that is, OEW before the customer adds various options
If a ferry is 'only' 40% over certified MTOW, it is unlikely that pilots would use max endurance power. Time to climb and best cruise altitude would be compromised. They require extra power until they burn fuel down to normal weights. Thereafter, power selected would typically be best RANGE (not endurance).
Ditto with brochure airspeeds - overweight ferries never achieve these (at least not until down to normal weight).