In the seattle area there are no convienant DEF pumps at the gas stations, but the 1500
i was getting about 8,000 miles to a tak of DEF. i just made it a habit if i went sotuh through Tacoma or west towards Spokane to stop at a truck stop and top off DEF, never went below ½ tank. The bonus, DEF at the pump is way cheaper, usually about $3/ gallon or less. Buying it at the parts store was 2-4 times more expensive and u had to get a funnel.