mileage took a dive
 

I thought I was doing so much better as my ScanGauge read 37mpg for this last tank and also showed that I used 12 gallons. I went to the station and pumped really slowly as I had read about here. To my surprise, it took 13.28 gallons to refill my take and knocked my mileage below 34mpg. Something is wrong; time will tell. I've used 1/4 tank since then only getting 33mpg.

um... oh no? just gonna complain or got some ideas about why?

If you pumped slower than usual, you pumped fuller than usual. Slower pumping is like topping off.

This is what I hope happened. I've never gotten over 13 gallons into the tank on a refill before.I looked up the tank size and it's 14.1 gallons; all those times I worried about running out for nothing. The only different thing I did this tank was more pulse and glide,which I thought helped. I just got 38mpg coming back from the grocery store( per ScanGauge). We have had some wind and rain lately and I did have to go into some shopping mall parking. That could account for the bad mileage on this tank so far.

Looks like it was the slow pumping top off that threw the mileage off. I topped it off again at about the same miles and got 35.8mpg; about what I had been getting recently. The ScanGauge was off again, but in the opposite direction; showing 32.9mpg. I'll have to keep on topping off to keep my gas log correct.

Sometimes I think the Chevron station I fill up at changed their calibration and charge me more for less gas!

I usually run my tank pretty low,so if it ever goes over 14.1gallons. I'm calling the Dept of Agriculture division of weights and measures.

I filled a 5 gallon gas can for the mower at the local country station a few years ago and they tried to charge me for 8 gallons. The pumps were WAY off.

Since i started a log on this web site and read others logs it seems the mpg will go up and down some what until we post many tanks to get a good average.

I had this suspicion once of a Cumberland gas station (I believe it's Gulf gas) I was so sure of it in fact, that I got a gas can and filled it up to the 5 gallon mark and logged how many gallons it took (about 5 gallons) and then emptied the gas into my car and did the same thing at the station across the street, filling the gas can up to 5 gallons again which was also a very similar number. So, to my disappointment, I had to drop that hypothesis.