Hi guys. I have some questions after I have changed my oil. Car has 50k kms, 1.8L MPI engine DOHC 16V The manual says it takes 4 litres, but after putting in 3.78 litres (4 * 946ml) and checking the level, it shows half way on the dipstick, even after letting the car run for 1 minute. Should I add a bit more or am I good leaving it as is since according to the dipstick it's fine? If I should put a little more, I want to top it off with 250ml dyno oil while the 3.78 litres I put are full synthetic. I already have a opened bottle dyno oil from my 2nd car oil change and I don't want to open another full synthetic 946ml bottle since I do low mileage and 1 year always passes before I need to change the oil. Anyone knows if this dyno dilution of aprox 6% only reduces the benefits of full synthetic by 6% or it's more? (because I don't know, dyno breaks down some of the chemicals in the synthetic, etc). So someone putting let's say 25% dyno and 75% full synthetic, is he reducing the synthetic effectiveness by only 25% or it's not a proportional ratio? Both oils are same brand, weight. Lastly, when I changed my oil, before doing that I checked the dipstick. I noticed all the dipstick was full. When I dropped the oil into the pan, it also foamed at the top. I don't know if it was because of the height to the pan, but I read that overfilling causes foam and my 2nd car oil change didn't foam, and I did see on the dipstick that oil was overfilled. Before doing this oil change, I took it to a indie mechanic, and I know it's my fault for not checking the levels after or every month, but I did 10k kms before I changed the oil now... Luckily car sounds and drives fine but there could be possible damage done already? I really don't know if foam at the top of the oil pan means anything or not. I have attached a picture. But maybe if 3.78 litres show half dipstick, maybe them putting 4L and a little extra directly as per the book took it close to full?