Just checked Gas Buddy for Knoxville TN diesel $3.99 - $5.39
Truck stops are the highest even when next to a small station with diesel for $4.99 but cant get a truck and trailer near the pumps. And the small stations would take an hour to fill those big tanks. Tried to get 35 gallons with a $1 discount and the store stopped my card at $125.00. 3 1/2 gallons short.