Originally Posted by
DA201
A 787-9 should definitely be able to fly SFO-SIN nonstop as its range at MTOW is 7635 nmi, and the route is only 7339 nmi.
That does not mean the aircraft can handle the route. You need a substantially larger cushion than that.
Personally, I'd rather not be on the aircraft that runs out of fuel due to inbound congestion at Changi or stronger than usual jetstream.
Edited to Add: Here's a link to Boeing's marketing info on the 787's real world range.
787 Range - Los Angeles;
Seattle. You can see SIN is outside the shaded areas from both LAX and SEA.