Just finished my drive from Vancouver to Palm Springs. Day one was after work and through heavy traffic, so didn't really make much time, though consumption was super low.

Next morning was a 923 mile drive  for 12.27 h at an average speed of 74 mph using 26.8 mpg. I did refuel once, but to be honest my bladder couldn't last much longer. Only a diesel can do that, in this case my old Mercedes ML. To be fair the old goat is not the fastest but once it moves, not too bad.

For Europeans, 1500 km, average speed over 12-1/2 hours 120 km/h and consumption was 8,7 L.