You are driving to the supplier and then job to job . You dont need or want to run at 70 mph . Slow and steady wins the race . I have been at it for 30 years plus , 99% of my trucks and vans have been and are gassers . I had a 7.3 naturally asperated dually , it was fine but the rust got to it . I dont need a "cool" truck . My gas trucks do the job just fine .