Bought a Focus TDDi last week, 100k miles but full service history, well maintained etc.

Went to Bootle today for work and back, 400 mile round trip at 70/80mph. Heard that diesels do use more oil than a petrol so checked the level when I got back and whilst it had dropped a bit (not alarmingly so) but I did have to top it up.

Normal for a diesel ?