just shone a torch down through my oil cap, looks very clean and new but I can see marks on the cam :( its a BF with 89,500km. I bought it June 2009 with 26,000km on it. The oil was changed every 4 months (3 times a year) which is about every 4000km, until a few years ago when I changed to 6 monthly changes which is probably 5500-6000km. At first I used Nulon 10w40 for about a year, then Castrol Edge 0w40, then after it got tuned (280rwkw) Edge 10w60. Now I hardly drive it, so it doesn't get driven hard/hot I use the same Amsoil 10w40 that Rednose uses.