it's been like this since I got it. I have only done regular maintenance on it since I got it less than a year ago. the van is unmolestered, lol. nothing on it has ever been apart. I got it with 42k on the odometer. clean title, and it used to be a rental vehicle before I owned it. I was hoping to dig up as much info as I could to aid in a diagnosis before I make repairs. this weekend I am going to log a bunch of data on a good road test, then I will see what my ltft's are doing under different conditions. also, I have filled the gas tank and reset trip odometer. when it gets to 1/2 tank, I will refill and do some math and figure out what I am getting apart and away from the trip computer.

 

My 08 Uplander has had a sudden decrease in mpg. Also seems to really accelerate more quickly from a stop. No errors/ check engine light, no visable gas leaks...
Has anyone found a cause?