15 QT 15-40 Rotella
At full load a new 400 kva genset will use approx 80 Litres /hr, at 75% load approx 62 L/hr and at 50% approx43 L/hr...assume 0.8 pf
60%
It's 9 gallons per barrel of oil.
You may have a bad injector/s leaking diesel past your pistons and mixing with your crank case oil...... pull the dipstick and "sniff" it.... you will smell the diesel.