Is there that much difference in fuel?

[chris142]

I always check my milage.its been 11.6-12.3 for a long time now.i always use the same pump at the same station.

The station was packed this morning so i went down the street. Did my usual trip and filled up tonight.

Suddenly im getting 16.37 mpg. The only difference is i fueled at a different station. I made sure that it was full.

I did notice that the truck seemed to run smoother on the fuel i bought today.

 

[Clb]

Bump
Curious, I got nuthin.

 

[icanfixall]

Without knowing what blend of fuel you usually use its not possible to make a statement. What I can suggest is use this new fuel station another time. If the second fill up gets the same mileage I sure would never buy from the "other place".

 

[HS108]

Fill up again at the second station a few times, pumps could be different or off, your in socal so I doubt its a summer vs winter blend difference.

 

[IDIoit]

what were the names of the stations?

 

[Clb]

what were the names of the stations?

Dowecheatem andhow
Think stooges

 

[whitehorse]

Could be foamy fuel at one and good fuel at another maybe...?

 

[Golden Helmet]

Could be foamy fuel at one and good fuel at another maybe...?

^ That is probably it, I've encountered almost the exact same thing the OP has and it was due to foamy diesel throwing off my numbers. Normally I fill up at Chevron, which pumps reasonably fast but always puts a half gallon on the ground due to the foam. I filled up once at a Valero station, it took half an hour to fill my tank but it was actually full. My next fillup after that was Chevron again, and my hand-calculated MPG on the Valero diesel came out to around 16MPG; since I couldn't fill my tank to near-100% at Chevron like I did at Valero thanks to the foam, it gave the illusion of higher MPG on the Valero diesel.

It's a pain in the ass trying to calculate MPG when you have to deal with foamy diesel crap. Usually after the foam spills out for the first time, if I pump slowly I can fit an extra 3-4 gallons in my tank before more foam spits out. I never know for sure if I'm completely full, but with a 45 gallon rear tank, who cares, I'm not running out any time soon

 

[chris142]

My usual gas station is a fastrip.its supplied by chevron.Theres only 2 suppliers up here. Chevron and shell.

The 2nd place is usa gas.dont know who there supplier is.i assume shell.funny you guys mention foam. The fastrip always foams but i keep going till i see fuel in the neck.

 

[Clb]

^^^ there's the trick!
Get the wet fuel in sight every time ( not thr foam) and the tank will allways hold the same amount!

 

[whitehorse]

I drive a truck for a living so different stations have different flow rates on there pumps. The fast ones are nice but the foam will kick the pump of quicker and then when I get in the truck and crank it, the truck won't be completely full.

 

[Number21]

You definitely need to run a few more tanks before you can really be sure of anything. 11-12 sounds pretty low though, my '83 gets 15-16 and it's in really bad tune, plus a ton of idling.

 

[chris142]

Ok heres what i did. Filled up again at the station that gives less mpg. Got 12.3mpg that tank.

Filled up again at the station that gave me better mpg. Did lots of steep hills,2nd gear full throttle.lots of intown driving and some idling.

Got 14.5mpg.

Definitely a huge mpg difference between the 2 stations.

 

[turbo elk]

Or somebody's pumps aren't calibrated properly.

 

[Thewespaul]

my 5 cents on this

I have noticed that the "sooner" I fill up my truck from when they last filled the station's tanks the worse my trucks performs.

My thoughts are that the act of filling the underground tanks disturb sediment that will be sucked into your fuel system

Thus, the more time the station's tanks have to settle the greater your performance?