Just went through a tank of fuel since the PCM update... Wow! I hand calculated it to 17.1 mpg. I was getting roughly 14.4-15.2 prior to the update. I haven't changed my driving habits and I am still driving in stop & go traffic on mostly short trips. I get it out on the highway every few days for at least 30 minutes. Cana PCM update cause that drastic of a mpg change? Maybe she's breaking in a little better now that her throat got cleaned out.

 

usually you will get better around 10 to 15k miles