Hey guys I'm running and 05 Freightliner Classic XL with a 435 twin turbo Acert C-15, 13 speed, and 3.55 rears. I've been trying to get better MPG and power out of it but I just can't seem to do it. I've tried a few different things from add ons like Air Cells, Turbo 3000 D, to changing driving keeping it under 14-1500 RPM while cruising. I'm debating on converting to single turbo but not really excited about spending upwards of $9k. Anyone got any suggestions?