I just filled my '21 Rubi 's DEF tank this afternoon for the second time since delivery. Currently at 6500 miles. First DEF fill was at 3000 miles (full at delivery). 8.753 gallons total; 745 miles per gallon. Pretty much at the 3% fuel consumption mentioned previously. I too feel misled by Jeep that refills would only be required every 10k with oil changes. My '18 WK2 ecodiesel would go 10k between, but with a 30% larger DEF tank. Still had a much lower consumption rate than the JL.