Just completed two long tows since installing the EZ. Both from central VA. to Albuquerque. Made same trip last fall without EZ, so can compare. Pulled a 20' gn horse trailer with loaded tack room and 4 horses. Second trip was with a 34' enclosed race trailer. Both weighed around 10k, but car trailer had more frontal area for wind resistance. Facts and opinions-- Horse trailer mileage, best 13. 3, worst 12. 2. Car trailer best 12. 8, worst 10. 4 (strong head/crosswind. Speed was consistently between 70 and 75. Max EGT's 825(post turbo). No trouble slipping clutch, but eased into it and kept rpms above 1700. This was on a 2001 ETH, basically stock except for EZ and 4" Jardine. Impressions-- EZ definitely worth the money for increased tow power and ease of installation. Seems to give about . 5 to 1. 5 mpg increase. On a side note, the truck now has 46,220 miles since April 1, 2000 without a lick of trouble. Steering remains tight, no squeaks or rattles. Has not been back to the dealer for anything. OEM Michelin 265's are wearing incredibly. Look to have around 15 to 20k left on them. Best truck I've had (this is my 5th Dodge w/Cummins). Only negatives-- smacked a deer Wed. morning and bent right front bumper. Best positive--smoking a Powerstroke on the long grade out of Charlottesville.