I am a mechanic and own my own shop, my trucks mileage went for good to 10 mpg if I was lucky. I did every thing I could think of and even talked to what I thought was the best brains around to learn more. It seems no one knew what caused poor mileage, Alex at Banks even told people to call me at my shop to try and learn as much as I had on the problem. If I wern't a hard headed Irshman I might never found what the problem was. I am getting to old to play with it, but in my younger day I might have tried for 25 or even 30 I do believe it is very posable to reach that number with the proper modifation.