Gentlemen, I bought a BMW E60 with a 2.2 170 hp engine with a gas installation. The previous owner was flooded with oil Elf 10W40 and while browsing various forums I read that the only right oil for this engine is 5W30 or 5W40. At the present moment after driving some 2.5 thousand km the car took some 300-400ml of oil. My mechanic claims that if he is getting oil now, there is absolutely no change to 5W30 because he will take even more. What do you think about this?