Illogical Fuel Economy

All the vehicles I have owned up until my Lexus ES 300h lost fuel economy the faster I drove. Much to my surprise and delight, the ES 300h gets better gas mileage at 65 mph than 45 mph. Here's the explanation I found online: "The Lexus ES 300h often achieves better fuel efficiency around 60-65 mph than at lower, stop-and-go city speeds (45 mph) because its hybrid system operates at peak efficiency in a constant, moderate speed range. While lower speeds minimize wind resistance, the Atkinson cycle engine and hybrid battery system are optimized to run at maximum efficiency at steady, moderate highway speeds, reducing the need for constant, energy-intensive accelerating and regenerative braking cycles."

In stop-and-go driving around town, I get 45-47 mph in economy mode. I have yet to take a day long drive on an Interstate, but I am thinking it might get 50+ mph. In my opinion, it's better than an all electric vehicle and eliminates the "range anxiety" associated with them.