So I was finally able to get the gulfstream.com product pages for the new models to load and did this little comparison:
Am I missing something? Less than 3% lower fuel consumption per mile even after sacrificing all that range, all that cabin size, and having brand new clean sheet engines versus the G650 launching with engines that were already almost 20 years old? Also, an article I found on AINOnline claims that G600 M.90 range is only 4,800nm, a much higher percentage of range loss traveling at M.90 versus M.85 compared to the G650/ER.
I don't get it. Even if they just strapped these new engines onto the G650ER they should have gotten more of an efficiency gain than that. Shouldn't these new engines alone be good for at least a 10% increase in specific fuel consumption? That seems to be the case whenever commercial airliners are re-engined from something as old as the BR700s were to something brand new.