TD5 would be the newest engine I would personally consider, older engines are just simpler to fix. The TDCI is without doubt the quicker and more refined engine, but I have heard rumours of them not being able to cope with the abuse they tend to receive as a works vehicle.
A decent remap will improve MPG as long as you don't use the extra performance all the time. My old Focus ST would achieve about 25/26 MPG when it had 225bhp and 320nm, and driven in the same manor achieved 27mpg when it had 315bhp and 560nm.
A decent remap will improve MPG as long as you don't use the extra performance all the time. My old Focus ST would achieve about 25/26 MPG when it had 225bhp and 320nm, and driven in the same manor achieved 27mpg when it had 315bhp and 560nm.