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View Full Version : Gas Tank Volume -- Really 20 Gallons?



ptcflyer
03-20-2005, 11:58 PM
I have had four refills. The Fuel Mileage indicator indicates out of gas...with only a few miles remaining til empty and when I refill, I can only put in 18 gallons max.

Is there a 2 gallon reserve beyond the distance to empty indicator? Is anyone else experiencing this.

I am driving an M45 non-sport.. ???

2001_S15
03-21-2005, 01:46 AM
My G35 has a "20 gallon tank" and yet the most I ever seem to be able to put in it is 17.5 gallons.

kennycrudup
03-21-2005, 02:29 AM
The Fuel Mileage indicator indicates out of gas- with only a few miles remaining til empty and when I refill, I can only put in 18 gallons max.


My FX45 is like this. I'm assuming it was engineered this way- and like everything else that just belies common sense, it was probably done as a measure to avoid lawsuits in case some dweeb decides to sue 'cause he got stuck somewhere on empty and thought he could make it to a gas station. I've been "at the mark" once in my FX (which I believe has a 23(?)-gallon tank) and was able to only put in 19.5 gallons.

Q45tech
03-21-2005, 04:42 AM
For 20 years since my 85 300zx Nissan has always used a 2.5 gallon reserve [allows 50+ miles at slow speeds], my 90, 95 Q had a separate sensor as did 85 as a final warning.

Every car will show minor changes [differences] in linearity of the fuel level arm vs dash reading.

TheDon
03-21-2005, 06:18 AM
often wondered about this on every car. If you read the window sticker, fuel cell capacity is always listed as "approximate".

Must be the characterisitics of expansion, contraction, vaporization, and the search for my critical mass.

Mike_TX
03-21-2005, 09:23 AM
Every car has a sizeable reserve these days, and yes it's for legal reasons.

But aside from running out of gas, getting really really low is bad because it allows sediment in the tank to be sucked into the fuel filter and maybe even into the injectors. That sediment often contains a good bit of water from normal condensation, and being heavier than gasoline, it hangs around on the bottom of the tank and combines with other trash to form a gooey crud. By keeping a couple of gallons in reserve, this flech doesn't make it to the pickup tube, so it stays out of harm's way.

In cars that give you the "distance to empty", it's interesting to watch it go to "0" and see that the car is still running. http://forums.freshalloy.com/images/graemlins/wink.gif I didn't do this on purpose, but I once ran my Beemer into the negative numbers on a trip. That was scary.

340HP
03-21-2005, 03:18 PM
Heh, I didn't pay attention to my fuel gauge once in my 1993 Q45a and ran out. Thankfully I was rolling down-hill (huge hill) and there was a gas-station right at the bottom. I filled it to the max, as the manual stated (forgot right now what it was).

Starting it was a pain in the ass. Had to crank it for like 2 minutes and it sputtered a lot before finally catching on smoothly.

Heh, close one.

biggstuu
03-21-2005, 03:29 PM
I have had four refills. The Fuel Mileage indicator indicates out of gas...with only a few miles remaining til empty and when I refill, I can only put in 18 gallons max.

Is there a 2 gallon reserve beyond the distance to empty indicator? Is anyone else experiencing this.

I am driving an M45 non-sport.. ???



Maybe im missing something but why even run the tank down like that? On a new M at that? Im thinking about the sediment/buildup thing and then, even worse the sheer sight of your m pulled over on the side becuase you ran out of gas. Oh the horror!

CODYTM45
03-21-2005, 08:57 PM
With my 2005 RL, which also has a 20 gallon tank, I never ended up putting move that 16.5 gallons in it. Even though the light came on and my distance to empty stated 0 for a few miles. I agree that there is a big reserve in there in these new cars to make sure we don't run it close.

D_Nyholm
03-22-2005, 12:55 PM
Running it to near empty will not cause the pickup to pull the crud out of the tank. THe pick up is at the bottom of the tank so it does not matter unless the 'gunk' is lighter than the gas and floating on top. Just an observation....

In the G35, I have put a little more than 18 gallons in it. The light comes on about 17 gallons and I usually will drive another 20-30 miles after the light comes on.

Mike_TX
03-22-2005, 01:45 PM
Running it to near empty will not cause the pickup to pull the crud out of the tank. THe pick up is at the bottom of the tank so it does not matter unless the 'gunk' is lighter than the gas and floating on top. Just an observation....

In the G35, I have put a little more than 18 gallons in it. The light comes on about 17 gallons and I usually will drive another 20-30 miles after the light comes on.




I've been led to believe the pickup moves with the float arm, so that when the level in the tank is low, the pickup is near the bottom, but it's higher in the tank when the gas level is higher.

Correct me if that's wrong. http://forums.freshalloy.com/images/graemlins/confused.gif

'97 S14 SE Turbo
03-22-2005, 04:12 PM
I've been led to believe the pickup moves with the float arm, so that when the level in the tank is low, the pickup is near the bottom, but it's higher in the tank when the gas level is higher.

Correct me if that's wrong. http://forums.freshalloy.com/images/graemlins/confused.gif



You've been lead wrong. The pickups are set low in the tank, and none moving. No reason to skim the top level of fuel, when 1 none moving pickup can do the job perfectly.

D_Nyholm
03-22-2005, 04:43 PM
Running it to near empty will not cause the pickup to pull the crud out of the tank. THe pick up is at the bottom of the tank so it does not matter unless the 'gunk' is lighter than the gas and floating on top. Just an observation....

In the G35, I have put a little more than 18 gallons in it. The light comes on about 17 gallons and I usually will drive another 20-30 miles after the light comes on.




I've been led to believe the pickup moves with the float arm, so that when the level in the tank is low, the pickup is near the bottom, but it's higher in the tank when the gas level is higher.

Correct me if that's wrong. http://forums.freshalloy.com/images/graemlins/confused.gif



What bunny boy said!! http://forums.freshalloy.com/images/graemlins/wink.gif

Mike_TX
03-22-2005, 04:57 PM
Okey - doke! Corrected I stand.