Hey mackpro I do see a fair jump in power and not much change in the fuel I use, I also went with the turbo they offer. i had the inj. tested when I got them, mack said they didnt have much life left, so took them to local inj. shop they said they were good and set up pressure in them. the price from rochester is good. Im going to adjust the waste gate to get a few more pounds of boost though, it only gets to about 33psi on a hard pull. check out Illios dyno center http://www.idc-solutions.net/MackE-7DieselPerformance.html#MACK ETEC etech performance power chip module they have this to say 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Mack E-TEC ETECH - All Models - Power - Mileage - Performance Chip - ECM Re-Flash Tuning & PLUG-IN CHIP MODULES! We now offer precise engine management tuning for all 1998-07 MACK ETEC engines, by re-flashing your ECM for more Power & Better Fuel Mileage! - $1250 Requires Removal & Shipment of your Truck's BOSCH Engine Control Module to us for precise engine tuning. Safely Adds from 15% up to 30% More POWER! - with Power increases of 50HP, 75HP, 100HP, 125HP, or 150HP! - Your choice! Send us your ECM, along with the increased power you need, and we'll make it happen! Please allow 3-5 working days for return delivery. If you have any questions - call us at (309) 523-9200 PLUG-IN CHIP MODULES - 1998-2008 ETEC Our ADJUSTABLE PE-18-MACK Plug-In Chip Modules add 40-100HP: $1495. NOTE: These Modules require connections to the fuel injector wiring & take approximately 1 hour to install. Ive been wanting to call them to see just what they are doing, maybe you can call them? see what they say? Its funny that mack could make marine E7 with hp up to 900hp, I know its water cooled, but it must have different electronics, Id love to find one and rob it!! maybe barry can start a forum on hopping the E7 up? bobo