Best mileage occurred stuck in a traffic jam, creeping along on the electric motor.
A couple of weeks ago I was able to test drive Ford's Escape Hybrid gasoline/electric SUV. This vehicle marries SUV size with Toyota's parallel hybrid power train that allows running on the electric motor (the 4-cylinder gasoline engine shuts down) during low power demand.
A portion of my time in the Escape was spent driving to Cape Cod on the way to catch the Martha's Vineyard ferry--along with the usual abuse from the Steamship Authority. Punching up and playing with the mileage display, I recorded around 29-30 miles per gallon doing 75 miles per hour, both with and without the air conditioning on and hauling four people. Best mileage occurred when stuck in a traffic jam, creeping along on the electric motor, which pegged the gauge at "unlimited." Checking fuel economy by seeing how much gas I put in the tank, my total mileage, over 267 miles of mixed highway/suburban driving, was just below 28 mpg. EPA mileage! numbers for the two-wheel drive Escape Hybrid that I drove are 36 mpg city and 31 mpg highway. The four-wheel drive version gets 33 mpg city and 29 mpg highway.
The SUV also uses an electro-hydraulic braking system supplied by Continental Teves. The system stops the vehicle by using regenerative torque to recharge the hybrid power train battery, supplemented with friction brake torque. This system not only minimizes braking distance but produces no brake pedal vibration when pushed hard into the ABS mode.
If you want to learn more about hybrids and other "green" automotive technologies, go to the blogs at the Green Car Congress.