my little thing with OD if i'm pottering round town or in heavy traffic (stop/start) i drive with the OD off. I have noticed the car will reposed a bit quicker on teh gear changes if you need to give it the beans (like fast lane changes) once i'm crusing along at a constant speed (freeway / open road) flick the OD on, so the gear box and motor relax and save some fuel. remember OD has no power behind it, so the gearbox will kick down if you give it a boot full. Also, for those that are lucky and not have OD but have a auto, try this on for size. Family member of mine drives cabs in SA. everytime he comes to a stop, he knocks the auto into "N". I asked why, he explained that the auto clutch is still engaged and slowly burns the auto clutch therefore wearing the box out. Just be carefull not to knock it into gear and then gun it. Wait for the box to engaged!!!!!!!!!!!!!!!!!!!!!!!!!! my 2 cents