I specifically signed up on this website to voice my disappointment on my gas mileage. I bought a 2004 Trailblazer EXT in May 2004 and I'm getting @11 to 12 mpg in City driving and @ 14-15 mpg on the Highway in California. I've took the Trailblazer back to the Dealer where I bought it, and they did not find anything wrong with it. I've tried different brands of gas, even added a Tornado, but still lousy gas mileage. If anybody out there can recommend something let me know.