So, I was doing some number crunching. I track every drop of gas that goes into my RAM. I have been doing it ever since gas has been more expensive and it started putting a dent into my budgets,lol. I looked back at last year and for the first 4-5 months, May of 2011 was the first month at wich I hit the 14 mpg for the month average, give or take a few 10ths of a gallon. I have hit the 14.1 mpg average in March. The real big difference between this year and last year as far as I can see. This year I bought the DiabloSport InTune for my RAM. I have been running Shell 93 for the last few months as well. I have the tune set to the 91 tune. I have squealed tires, driven kind of not so conservative and have towed a boat (50 miles round trip). Unless they started the summer mix back in Feb-March. I live outside Toledo,Ohio. I am not sure when summer gas gets brought back, so I can not explain if it is here or not. I know this, I hit a mark early in the year, with the 91 tune. I have yet to try the 87, or the MPG Booster tune on the RAM. I will say this, if you are thinking about buying one for your 2009-10 RAM, do it. Well worth the 389 I paid for it. I have already spent less on gas this year, so far almost 120.00 dollars less. IF I can average that savings every 4 months. I have paid for it.