better gas mileage with the fuel neck plum full?

[warlocke]

i accidently filled my fuel neck up 2 tanks ago and when i filled up this last time i got 32mpg, i didnt fill the next a few days ago when i filled up, and i just got 28mpg even, i filled my fuel neck plum full again just to see but has anyone else done this?

[GenevaDirt]

you are not going to get better gas milage filling the neck....you will just be able to go further on the tank of gas you did that on. Only true way to measure you mileage is to fill it the same way everytime. I would run the car down to empty and have 2 gallons of gas with you and be somewhere you could get to a gas station within your estimated mileage. Put the gallon in and drive till it runs out....you will then know your true mileage. Then put the other gallon in and head for the gas station.

[Festiva_tunner]

the reason you got better milage is because your basing your readings off of a 10 gal tank and now you have 11 in it, also after a while of doing this your filler neck may start to leak and dump gas into the cabin

[Gomez]

Running out of gas is bad for the fuel pump! But it is the only exact test for mileage. I usually fill the neck up to the same place every time and do the math based on how many gallons I put in.

[neanderpaul]

^ +1 on both counts

[NovaSS]

gas is heavy, the more fuel in the tank the more weight you are draggin around so your milage will be less.

10 gallons weighs about 62 lbs

[25Horseplay]

The best way to determine your fuel milelage is fill it up and write down the milelage. The next time you fill up divide the miles you traveled by the gallons you just filled up again. Example if you went 300 mis and bought 7.5 gallons then 300 divided by 7.5 equals 40 MPG.

[warlocke]

well i do keep track, i enter all my info into a program that calculates it, ive dbl checked it and it is acurate

[Festiva_tunner]

what program?

[warlocke]

its called automotive wolf, you have to buy it, but it keeps track of your service intervals, reminds you when stuff is due (providing you enter some of the things) and keeps track of the health of the oil and coolant and stuff.

its worth it, i dont remember what it costs tho.

[Festiva_tunner]

where did you pick it up at?

[warlocke]

http://www.lonewolf-software.com/automotivewolf.htm (sorry to advertise lol)

thats the programs website, 30 bucks for a legal copy.

[Pu241]

well i do keep track, i enter all my info into a program that calculates it, ive dbl checked it and it is acurate

Only as accurate as the data entered!

SETI is wondering where you went?
Make a team then drop out of sight!

[warlocke]

i barely have time to get my server back up and running lol, i have not touched it in a cpl months

[roycehof]

The better mileage reading is most likely that you didn't put as much gas in the second time. The mileage reading should be averaged over several tanks. I notice that mine varies quite a bit (anywhere from 42 to 49). That is why when people ask what kind of mileage I get, I just tell them mid 40's. Oh yeah - bad idea to run a fuel injected car completely out of gas. Tends to do nasty things to fuel pumps. I always try to keep my tank above an eighth of a tank.