One of the tuners over at the COBB forums has been putting some effort into making big power, while still pulling close to 40MPG. The direct injection allows him to lean out the AFR at low load/crusing, without increasing EGTs/cylinder temps. I haven't seen proof, but from what I've read he seems to be a pretty reputable tuner. It's like having your cake and eating it too
More discussion here: https://forums.cobbtuning.com/forums...7-Economy-Tune
Direct injection really is the future.