Hello friends, would have a question to you. The story has a small background, so first of all a small introduction. I also have an oldtimer tractor. Built in 1950, It is an oak, single cylinder, 1.2 l cylinder capacity, 13 hp, air cooled. With that I drive the prescribed HD40 single-range oil of the brand Tectrol. My neighbor drives a VW Golf 6 with the 1.4 l, 80 hp engine. Yesterday he came to me, and asked me about engine oil because he had to refill something with his car. I told him I only had the oil for my oldtimer Schlepper. And that’s an HD40. That’s what he meant. He fills the oil with the HD40 otherwise also in his car. He runs very well with it, so without any problems as he told me. However, he only leaves it in the summer, then you get HD30, so the single-range oil for the winter, because he only bad starts with the 40 oil in the winter. When I told him that it is not allowed for his engine, but he didn’t tell me that he didn’t have a lot of oil?