Today, for the first since I bought my 2009 ES 350 (19,000 miles) in February, I had an opportunity to go on the highway.
I set the cruise control at 62 mph (100km/h) for 240 miles and obtained 30 MPG (US), or 36 MPG (CAN) or 7.4l/100km.
Driving strictly in the city (no highway at all), I manage 22 MPG (US), or 26 MPG (CAN).
One thing I find fascinating as well as puzzling, is the following: When driving on the highway, the engine RPM was constant at 1,800. And when I drive in the city, I basically never go higher than 1,700 RPM. I tend to stay between 1,400 and 1,600 (yes, I am the slowest driver on the road - and at the next traffic light, I catch up with at least 80% of all the drivers who passed me ;) I basically never reach 1,800 rpm during my daily commute and yet, I am having a lower mpg.
In the past, I always had higher mpg on highway compared with city, but that was when I was driving a European car and I was driving like a freaking maniac reaching rpm in the 3,000 from every traffic light. I always was the fastest kid on the bloc.
I forgot to say, I only use regular (87) gas.
Anyway, your 2 cents is welcome.