[Ptero]

Testdrive is right. Your car must be described in the operator's manual as capable of being "flat-towed" or you severely mistreating your transmission. Even then, automatic transmissions are not designed or tested for being shifted in or out of gear at speed. There are other stress issues involved with these highly complex and delicate devices. I have seen Detroit cars with automatic transmissions lose their higher gears from being coasted several miles. I would never, never coast my automatic vehicles in neutral - even if they were described as being capable of flat towing. This is because flat towing does not involve putting the car in and out of gear at speed. My advice, don't do it. Ever. Period. If you want better mileage, get a manual or, better yet, an automatic manual transmission like the Smart is equipped with. That is the coolest high mpg transmission ever made.