I'm ****ting it a bit now. Mines is a 2013 e92 and hadn't noticed any oil usage in the 6 month I had it till recently. It was below 75% so I topped it up, just small amounts over a few days. And then almost upto a litre added about 5 days ago. There was barely no change in reading, I checked again today and noticed it's now at max.
No warning lights but that's really worrying me now so I might phone my local bmw for a quick look. It's ridiculous there's no dipstick.
From the Owners manual. (May help reduce the some of the problems with the less than perfect electronic oil level monitor).
Do not add 1 US quart/1 litre of engine oil until the display shows an oil level measurement of "+1qt" or "+1l".
Add oil within the next 125 miles/200 km, otherwise the engine could be damaged. Add no more than 1 US quart/1 litre of oil, otherwise too much engine oil can lead to engine damage. Add at least 0.5 US quarts/0.5 litres, otherwise the oil level monitor will be unable to display the new value reliably.
Checking oil level
Your car is equipped with an electronic oil level monitor. The oil level can be displayed when the engine is warm. Continuous short distance travel or a very sporty driving style may make measurement impossible.
1 Oil level OK.
2 Oil level is being checked. This can take about 1 minute if the car is at a standstill on a level surface, or about 5 minutes while the car is moving.
If engine oil was added, it may take up to 30 minutes to obtain an oil level reading.
3 Oil level down to minimum:
Add engine oil at the next opportunity, but no more than 1 US quart/1 litre, refer also to Adding engine oil on page 61. Add at least 0.5 US quarts/0.5 litres, otherwise the oil level monitor will be unable to display the new value reliably. If the oil level is below the minimum value, add engine oil immediately to avoid engine damage.
4 Oil level is too high.
Have the vehicle checked immediately, otherwise the excess oil may lead to engine damage.
5 A value cannot be read at this time. The engine is not yet warm.
In addition to the automatic measurement, you can also determine the current oil level manually, e.g. after adding engine oil, but such measurements are less accurate.
1. Park the vehicle on a level surface with the engine at operating temperature, i.e. after an uninterrupted drive of at least 6 miles/10 km.
2. Let the engine idle.
3. Press the computer button in the turn indicator lever repeatedly until the oil level display appears in the instrument cluster.
4. Press the computer button for at least 2 seconds. The oil level is determined. A clock symbol appears during measurement.
5. After approx. 1 minute, the current oil level is displayed.