The real kicker for me is that both previous Passats were reasonably accurate.
There's no reason for me to be getting less than 35mpg out of this thing. I peg the speedo at 75 on the highway for my commute and out of 27 miles, it's about 23 on the highway. Newly reconstructed, 4 lanes each way, wide open. Like I said, the computer is showing what I expect. The manual calc is giving me something else. (I'm assuming that neither my calculator, Excel nor my phone are doing the division incorrectly.)
Unless I'm losing about a gallon of fuel somewhere (running *really* rich), I can't figure it out.
Here's what happened:
- Low fuel light came on this AM
- Previous experience tells me that low fuel light = approx. 3 gallons to go
- Trip computer shows me 35.3 mpg tank average
- I happened to stop within 10 miles of light coming on
- Important: I stopped at the same station, same pump as last fillup. Used same method to fill tank - wait until auto-stop, watch bubbles go down, then top off to nearest $0.25. (I dunno, I like seeing multiples of $0.25 on my gas card bill.)
- Get receipt.
- Do math based on both change to overall odo (47k miles) and trip odo (480 miles since reset/fillup).
If I did 480 miles on 13.5 gal, that's 35.5 mpg. The computer was giving me approx. 35.5mpg as a readout *and* 13.5 gal is about what I'd expect to have as capacity when the light goes on (presupposing 16.4 gal capacity).
Instead, I put in 15.5 gallons. Over 480 miles, that's a dismal 31mpg.
***?
If I were losing 2gal of fuel over the course of a week or so, there'd be a puddle in my garage. If I were running that damned rich, I'd be blowing smoke screens all over creation.
What am I missing?
