10W40 oil is very thin oil, very thin oil!

im 100% sure u burnt the oil while driving.

whatz the oil rating on the new bottle?

Manufacturers recommend the thin stuff, like 10w/40 15w/50 for mainly the new generation engines. Once you get some serious Kms into the engine (especially in your case LOTS of Hard KMS) that oil will just burn like news paper in a fire.

I wouldnt recommend anything Lighter than 15w/50 in your engine.. maybe even 20w/50 which lets the oil stay a bit at the top of the engine, over the cams and everything. 10w oil just drains right through back to the sump, and when u start the engine you wear it out with No oil up there (new engines allow for that).

Hope this helps!