Okay... I'll admit. I monitor my MPG on the Vehicle Status of my iDrive. I don't do it see how much gas I am saving but rather it gives me an indication of how aggressive I have been driving for that specific tank.
Here is the story. I live on the Jersey Shore and my area was one of the hardest hit by Hurricane Sandy. 1/2 of my town is still with out power. I filled up at a BP station last Saturday. I have never used this BP station before. The Hess station right next to my work was out of Premium grade for almost 2 weeks now so I had no choice but to go to another station. As I pulled in to the BP, my first question to the attendant (in NJ, it's full service so they pump for us) was if they have Premium. He said they just had a tanker fill their reservoir tanks last night and have Premium. Attendant pushes the Premium grade button and proceeds to fill my car. I notice the price for Premium at $4.15 per. Fill up completely and I am on my way.
I keep a log on www.fueleconomy.gov
for my MPG for every fill-up, how much gas needed to fill the tank, cost per gallon and total cost of the fill-up. For my last 10-records, I have been averaging about 18.5 MPG for those tanks with mixed styles of driving but it seems like no matter how hard I drive, I end up around 18+ MPG (I know... I'm not driving hard enough
). It has been almost a week now with normal driving with no aggressive sprints during my commutes to work and I have been averaging 15.4 MPG. A far throw from my usual 18.5 MPG. That's a pretty big drop-off. How can that be?
Did BP fill my tank with Regular or is there a huge difference in quality between BP and my usual Hess? I am now hearing stories how tankers will come to fill the gas station's reservoir tanks and if they are re-filling the reservoir tanks with Regular and the tanker still has some left, they'll just empty it out in the Plus or Premium reservoir tanks instead of driving back empty (either diluting the other grades or completing putting the wrong grade in the tanks). With my area being hit hard by Sandy, I can only imagine the chaos the gas stations have been going through. My engine seems to be running fine...