I prefer SVOboys responce over Blueflames responce. Although I'd really like to see some hard evidence vs. someone just saying it's crap, I haven't seen any evidence from anyone not selling something. In my expirience, pre-scangauge so I wasn't able to quantify it, the performance mods did not hurt my mpg, it pretty much stayed the same, much to my dismay
However I did gain plenty of midrange torque which might help the pulse's, but I really can't say for sure. I have been able to drop more than 2 seconds off my quarter mile time all while bringing my mpg on my commute from 27-28 to around 42-43 currently. I've learned that the return on investment for performance parts for mpg is not good, especially compared to the ROI for aeromods, which dramatically help mpg and performance for cheap.