I have a 2000 F250 Superduty and I was wondering if anybody has ever tried cutting four of the cyclinders off while running down the Highway to improve the mileage. I know that GM is starting to do that with some of their trucks. Is this possible? I was thinking if a guy could just shut off four of the injectors that this might work. Which ones would have to be shut down to keep the engine in balance? What about tapping into the engine overheat circuit that turns off half of the cyclinders in a coolant overheat condition? I realize that you would not do any of these things if you were towing something. Is there any aftermarket companies that do this kind of stuff?