All dipsticks are designed to show 1 litre from the minimum mark to the maximum mark... Its an industry standard.
I've been away for a week and read this thread now..... I honestly thought it was a wind up at first
Honestly mate, never ever take it for granted that an Alfa Romeo uses oil in the same manner as another manufacturer, they don't! and that's exactly why so many members have offered you the same advice about checking regularly.
If you wait for a dash warning light or a mechanic to tell you, then it is usually far too late to do anything about the damage.... It is one thing that Alfa Romeo owners accept, they have to lift the bonnet on these cars to physically check the levels, it isn't a car for ex-BMW owners who watch the service bar indicators to tell them
I drive a V6 156 now, it has only used 100ml of oil in 8,000 miles! Yet I check it every week and every 300 miles or so on longer runs, just in case... It's a good habit to get into
I hope you haven't got any underlying damage.... Just remember 1 liter between minimum and maximum and you will never over fill it too