| I would not go to synthetic. My reason being is if there are no leaks and you use synthetic, you will probably end up with a leak. I don't recomend it. 20W-50 regular is fine. Most likely the engine is running non-synthetic oil. I had a 1993 325is w/ around the same miles and I started using synthetic. The car ended up leaking oil into the spark plugs. I replaced the valve cover and went to non-synthetic and the car never leaked again. Synthetic oil has been known to find weak spots, which causes leaks. If the engine was new or rebuilt, I would say synthetic all the way. But, since that is most likely the original engine w/ 103,000, save your repair money or for the price of synthetic for extra modds for the car. I hope this helps. Good luck w/ the new ride. |