What size tires are you running? Did you go bigger before the Sniper install or while you had the Sniper. I am debating going bigger than 185/70/R16.First real road trip since the Sniper install. My tires are taller, 17.5% difference from the odometer. Average mpg for the last 3 months is 12.09 mpg. Best is 15.09 mpg (corrected). It doesn't seem very good but driving it is way better. It pulls grades like it never has before. Much less time in 3rd and not getting passed nearly as often.
The improvement in performance is remarkable. I'd recommend the sniper to anyone who is desmogging.