Thanks AquaTune,I'm what you call a Snowbird. Had this system installed on my ‘98 Chev. 2500 duelly with a 454 engine. And I haul a 5th wheel trailer. I do admit I was very skeptical and I've kept very precise records since buying this vehicle a couple of years ago. I was getting 6.2 mpg pulling the trailer and 7.4 without. After you installed the AquaTune system I'm now at 13.8 without the trailer and 12.2 pulling it. On my way back to Arizona I'm going to make sure I'll tell everyone I see about this.