Credible information has been hard to come by , HPSimpson. It seems logical that if they do not currently meet federal emissions that something will have to give in order to reduce emissions. Power, torque, driveability, MPG. On other forums, some said no change, but had only driven a few miles, and not towed, etc. Some who have been battling rough idle or surging said it seemed to make it worse, after a prior reflash had seemed to improve it a bit. One guy reported an MPG increase, but he quickly vanished into the sunset. Better feedback would help, for sure.