Originally Posted by
geosynchronous
All of this seems counter intuitive...you can operate three engines on less fuel, and you can complete HSI/MPI/overhaul on three P&W 307's for less than two BR 710's. Again, this data is according to Conklin & deDecker's Aircraft Cost Evaluator 2009 vol. 1.
When you think about it, its not really counter intuitive. The BR 710s are much bigger engines. They're making 60% more max thrust. So they use 20% more fuel and have 10% higher maintenance cost? Big deal, they're providing a higher thrust/weight ratio to an airplane that weighs 30% more. The BR710s probably have much better "thrust specific fuel consumption" than the PWC307s if they are only using 20% more fuel.
Still, it is amazing that the 7X weighs 30% less than the G550. Its smaller, but not that much smaller. They really build a good airplane.