Wow it's been a while since I've posted in a tech section. I sold my civic hx to a friend who drives weekly from Northeastern Ohio to Detroit weekly. I handed it off at nearly 300,000 miles. It's at around 320,000 now. He just bought a Forester for winter driving/battlewagoning. The civic still runs good other than some tired seals and a bad maf sensor. We've both been mpg nerds for a while and we've been talking about taking the motor out of the civic and rebuilding it, along with modifying it around efficiency. I remember reading a while back about a guy who built an EG that ran 55mpg with air and power steering. He had a turbo setup that ran as close to 0psi as he could get. While we have the motor out and disposable incomes, we wanted to try to replicate or beat that. My target is 60mpg. He's a little more ambitious. So my question: What would be the best size turbo for basically eliminating the need for the engine to generate vacuum? I'm leaning toward a new turbo oem to a factory dsm turbo. Since we're not worried about power figures I don't want to go overboard and buy a train turbo, but I also don't want to destroy a motorcycle sized turbo, and most of those that I've seen are 3 bolt flanged. Any thoughts?