The Nissan Path

I've had the truck for about 2 months now and today I decided to let her run down until the low fuel light came on because I was skeptical of the proportions of the 21.8 gal tank, and I still am.

So I was averaging 15.8mpgs and the DTE was showing 24 miles. The gas gauge was showing about 1/8 a tank. I filled up with 17.09 gals. That would mean that there less than 2 gals left in the tank when I filled it up. According to my count thats only a 19 gal tank then. Yes I topped it off and the needle was well above the FULL line.

Anybody venture a hypothesis?

nutbar78 wrote:I've had the truck for about 2 months now and today I decided to let her run down until the low fuel light came on because I was skeptical of the proportions of the 21.8 gal tank, and I still am.

So I was averaging 15.8mpgs and the DTE was showing 24 miles. The gas gauge was showing about 1/8 a tank. I filled up with 17.09 gals. That would mean that there less than 2 gals left in the tank when I filled it up. According to my count thats only a 19 gal tank then. Yes I topped it off and the needle was well above the FULL line.

Anybody venture a hypothesis?

the only way to know for certain would be to let it run dry, and fill it up from there (NOT a good idea!)
i can tell you that both of my R51s take approximately 17 gallons to fill at the point where the warning light comes on
my take on this is that at that point there is still 4 gallons left in the tank
i think the warning light comes on very early to err on the side of safety, and that there is really more fuel left than is indicated
i'm not a big fan of the DTE "feature" at all, and i don't think DTE is a good way to judge the actual amount of fuel left at any point

A good number have reported fuel sensor problems so an experiment like that can leave you beside the road waiting for AAA.

I agree, the DTE is way off when it gets down to the bottom of the tank. I rely on the fuel gauge and the trip odometer.

I suppose a 4 gal reserve is good when you are driving something that tends to avg about 16mpgs. Its usually my habit to add fuel when I get down around 1/4 tank. On the upside, costs less money at the fill up!

If you calculate the actual MPG you will find that your computer is off by about 0.5 to 0.3 MPG. This is a difference of about half of a gallon. In addittion, the computer program is geared toward a 3 gallon reserve and does not include this in its calculation. In other words it only thinks that you have 18 gallons in the tank to beginn with. Consider also that you are looking at real time data and the computer adjusts for accelleration and coasting so you will have a natural margin of error to include. Next time reset the computer and drive it down to the 0mile mark at which point you would still have 2 gallons left. Fill her up and repeat a few times. You will notice the computer will adjust for the overlap in miles.

hfrez wrote:If you calculate the actual MPG you will find that your computer is off by about 0.5 to 0.3 MPG. This is a difference of about half of a gallon. In addittion, the computer program is geared toward a 3 gallon reserve and does not include this in its calculation. In other words it only thinks that you have 18 gallons in the tank to beginn with. Consider also that you are looking at real time data and the computer adjusts for accelleration and coasting so you will have a natural margin of error to include. Next time reset the computer and drive it down to the 0mile mark at which point you would still have 2 gallons left. Fill her up and repeat a few times. You will notice the computer will adjust for the overlap in miles.

Knowing that the computer is only thinking that it is an 18 gal tank definitely makes sense, thanks!

CPLTECH wrote:A good number have reported fuel sensor problems so an experiment like that can leave you beside the road waiting for AAA.

Actually, if one does have the fuel sensor problem, you couldn't even do this experiment. When mine failed, I could have a fresh tank filled to the brim, yet the fuel gauge would say 1/4 of a tank left.

NVSteve wrote:Actually, if one does have the fuel sensor problem, you couldn't even do this experiment. When mine failed, I could have a fresh tank filled to the brim, yet the fuel gauge would say 1/4 of a tank left.

Thanks for the clarification. Good to know should mine decide to take a dump.

dte hits 0, fills up with about 17 gals or so.

im guessing there is about 4 gal in "reserve"

i would advice filling the tank there anyway, sucking the tank dry will lead to major headaches.