There are also "program" vehicles that dealers and Toyota lend to events and celebrities, visiting execs, etc. Those have to be listed as used and are always low miles.
I believe Clarkson beat it the most on the test track with something like 17mpg to 18mpg. In comparison, the EVO8 got less than 4mpg on the same track. So a 20mpg car got 3 point something (80% less), and a 50mpg car got 17mpg (66% less)... Yes you can beat the car into submission, but I don't think the OP will be doing that.