Hi Nick & Ursula, Its been awhile since I met with you last summer and purchased the second Aquatune but I thought I would give you my 2 cents on how its doing. As you recall I traded in my old version of Aquatune which had been on my ' 93 Jimmy which has 230K miles, for the new version and put it on my ' 04 Chevy Blazer. I could feel the difference in power and so could my son. Well this Christmas we took it back "home" to Iowa and as usual we went up I-35 at the pace of about 85 mph (made it to NW Iowa in 12 hours). I had an extra half gallon of distilled water and a bottle of Isopropyl along as well. I found it used less water cruising on the freeway than it does in town. I usually go thru a tank of gas and 2 qts water for 300 miles in town driving. But going 85 mph we made it to Kansas on one tank of gas and averaged just short of 21 mpg. And the Aquatune still had about and inch left in it too. Now EPA estimate for my Blazer says 16 city / 20 mpg highway and they sure don't go 85 on the highway when they test. I usually average about 18.5 in town driving but then my right foot seems to be lead footed a lot! Love that power. And recently I had some warranty work done on the Blazer at the Chevy dealer and when they opened the hood they saw the Aquatune and asked if it really worked. Well you know me, I "schooled" them on it. And every chance I get at the gas pump I'm showing other SUV owners what they can do to get better mpg and power and give them your site web address.