I personally have not operated the 40, only the 45. But I have used a contract pilot that manages and flies a 40 and he says they do Chicago-LA once a month and only when the weather is bad in LA and alternate fuel is required do they need to make a stop. The 40 has a lower BOW and MTOW and a much more aft CG so it gets to FL470 sooner and is more efficient in cruise than the 45. Those two factors allow it to pretty much match the range of the 45. It's worth talking to some 40 operators to verify.
I will do some more research on this. The book only shows about a 1500nm range on the 40XR without the fuel mods and it shows about a 1900 mile range on a straight 45. I dont see how it can be that much more fuel efficient to basically make 180 more gallons of gas vs. a 45. Its not that much smaller or lighter.
depends upon how much he is going to fly, 100 hr a year, the cheap airplane is more cost a effective, a 1000 hours a year the expensive airplane with good SFC might be the best buy. We found at $4.00/gal we would have to fly a 731 powered airplane over 100 hours per month to be cost effective over the GE airplane when you consider the capital cost that has to be justified by the hourly savings.
I am costing things based on 350 hours a year. If he ends up making 2 west coast trips a month thats almost 160 hours right there for the year.