Free gas??? Too bad.....

Discussion in 'Gen 2 Prius Main Forum' started by coolfire74, Jan 20, 2006.

  1. coolfire74

    coolfire74 New Member

    Oct 13, 2005
    Boston, MA
    Ok, I bought a 2006 #7 silver at January 2nd, as everyone here did, I got a free tank of gas per purchase. Only 2 bars left, so I drove to shell gas station, and refilled it last night.

    For the first free tank, the best MPG I got was from highway, about 54 mpg, but regularly, I only got around 38-42 in city. After I refilled with shell oil, guess what, I got 56 mpg in the city!!! I have not tested for highway, but 56 in city, esp in cold winter!!!! I am so happy.

    I am really wondering what kind of gas the dealer provide to us. With the shell gas, the mpg jumped from 38-42 to 56! It is really a big surprise to me.

    What you guys got with your first free tank? Did you see any improvement with higher quality gas like shell?
  2. c4

    c4 Active Member

    Mar 29, 2005
    Definitely- Shell gas vs. Imperial (Esso) shows a consistent MPG gain.. I normally use Esso gas simply because it's convenient (there's a station right down the street from work) and because I'm on a fleet program where I get a discount on all Esso gas purchases. Recently, since the gas prices have come down to a bit more reasonable level, I decided to try an extended test with Shell V-Power premium gas and over the last 5 or so tankfuls, I'm averaging 4.6L/100km in my Classic Prius, in a temperature range of -5 to -15 C.. This is actually *better* than my summer mileage. Some of this I can attribute to the Michelin X-Ice tires, which I chose to be "minus sized" width, but higher profile for better snow performance and lower rolling resistance, but this accounted for my expected winter mileage of about 5.5-5.6L/100km with Esso winter gas formulation going down to nearly summer mileage of 5.1-5.3 L/100km (I normally get 4.8-5.0 in the summer), so the only explanation for the 4.6 that I've been seeing for the past few tanks has got to be the Shell V-Power gas..

    I know that the normal explanation is that Premium fuel actually contains less energy, and certainly, the other times I've tried other brands of premium fuel, I didn't notice any difference, but there's something about Shell gas that doesn't fit the conventional mold..
  3. frankie_delaware

    frankie_delaware Junior Member

    Nov 20, 2005
    Southern California
    2006 Prius
    My first fill up after the dealer tank calculated out about 6 mpg less than the MFD showed. I suspect it wasn't quite filled up initially. The next tank calculated much closer to the MFD value.