Both senders are not accurate at all but the 280mm sender is better than the original 250mm sender.
They may send different signals at different cars but while the short version indicated 0% after 60miles (100km) at my M3W the 280mm sender needs some 120 - 140 miles to read 0%.
For me the only important reading is 100% after filling. I know it's some 400km (250miles) till empty. Usually I search for petrol stations after driving 300km.
Hannes once: Green M3W; 2013 now: Red 4/4 Sport; 2011 and some practical cars for use in real life
