I purchase a 1993 Isuzu Npr a year ago and will never ever go back to pulling a trailer again. I love it. However, I'm only getting 13mpg. It is a four cylinder turbo diesel automatic with the open bed and dove tail. I realize the fact that it is an automatic hurts the fuel mileage not to mention the 200,000 miles on it. Is anybody else using one and what type of mileage are you getting?