First time surf owner, chuffed so far!

[Albannach]

why is that?

If you fill it to the top mark, there's too much oil in the engine. It'll just burn off what it doesn't need and settle out half way. Probably where your extra litre came from?

[dieselboy]

ive never noticed that happen. i try and get it to as close as the F mark as possible without going over..
ive never let an engine get to half way, noticed it and then left it there - if its on 3/4 full ive topped it back up or done a complete change.

on either of my surfs though, ive never had to top up mid way between oil changes. a bmw i used to have i would sometimes need to top it back up. but this is because the oil would blow into the inlet manifold when engine speed was high.