By that logic, a 94 Cummins 160hp motor should get HORRIBLE fuel mileage, considering how weak they are in stock trim. But a 94 160hp motor can EASILY get 20+mpg. Being choked down and restricted definitely isnt helping the 6.5s MPG, but just because a motor is "weak" doesnt mean it will get bad MPG. The problem might be more relatable to the InDirect Injection of the motor, which doesnt lend itself to great fuel efficiency.
