Hi Further to my thread about my OM642 I have the following question please. I travel about 6000 miles a year. A lot of that mileage is stop start and short journeys where the Engine barely gets up to operating temperature. I understand this type of driving to be hard on Oils. Generally I change my Oil at 6 month intervals so it will have been in the Engine for around 3000 miles or so. Can changing the Oil at these intervals do more harm than good? In other words can you change your Oil too much apart from damaging your Wallet paying for the changes? Many thanks. Tikka.