Attention: TDR Forum Junkies On purpose, I ran my truck out of fuel to see how much it actually holds. My truck is still new - app 2200 miles total now (I figure no sluge in tank yet).
35. 5 gal - when the fuel pump nozzle 'clicked' off.
41. 4 gal - when I saw the fuel level on the bottom edge of the vent hole inside the neck (after spending 6 to 8 min slowly filling the tank).
Here are the facts:
*Outside temps avg 75 degrees/and using 'summer' diesel fuel.
*Ran the truck till it surged (and finally quit running as I pulled over).
*The truck was on a straight and level road at this moment.
*Added 4. 0 gal of fuel.
*Started the engine per the owners manual for an empty fuel filter (several turns of the starter, then released the key to 'run' while the lift pump continued to run. Then turned the key back to 'start' - it started after 3 revolutions from the starter).
*Reset the overhead computer 'avg MPG' and 'distance'.
*Drove 10. 0 miles to the nearest gas station that sold diesel.
*The truck was on level ground when being refueled at the pump.
*The overhead computer showed 10. 5MPG for that part (I was towing an enclosed car trailer).
*the pump nozzle at this station is the 'smaller' type on the 'auto' diesel pumps - not the large one found at the big rig docks.
*I filled the tank running the nozzle almost continuously untill the pump showed 28 gal - pausing and slowly pumped to 30. 5 gal (wanted to see when the gage needle showed 'Full' (I think the gage still laged - and the nozzle still had not 'clicked off').
*Continuously ran the pump at a high rate from 30. 5 to when it finally 'clicked off' - 32. 8 gallons indicated on pump.
*Continued to fill tank till the fuel level was at the bottom of the vent tube hole in the filler neck - 38. 7 gallons indicated on the pump.
Conclusions that I draw:
-with my short drive to the station I estimate that I used 1. 3 gallons: the fuel used in the actual drive and the fuel the lift pump put into the fuel filter when it ran a short while prior to start. (at least I think thats what it was doing). So that left 2. 7 gal left in the tank when I started to pump in the fuel.
-amount of 'usuable' fuel in the tank when the nozzle clicked off: 32. 8 + 2. 7 = 35. 5 gallons.
-amount of 'usuable fuel in the tank when the level was sighted at the bottom of the vent tube opening in the neck: 38. 7 + 2. 7 = 41. 4 gallons.
-Had I not slowed the fueling process near the end I think there would have been more foam to maybe cause the nozzle to click off earlier... maybe just over 35 gal total usuable fuel. Previous times in refueling I seem to add 5. 5 gal but mostly 6 gal of fuel when filling to the vent line hole in the neck... so this may not be the case after all.
Other Notes:
-When the 'DTE' on the overhead computer showed 0 (and it stayed on 0) I was able to drive another 43 miles from that point till the truck finally ran out of fuel. (BTW the DTE was probably reflecting my avg MPG of 11. 7 the previous 120 miles of driving part stop and go city driving and part highway).
-I had topped off the tank previously to the vent hole in the neck... and driven 511 miles when the fuel gage needle was just above the last white mark in front of the "E"... between 1/16 and 0 on the gage. (all but 220 miles of this was pulling my enclosed car trailer). When the DTE showed 0 the gage needle was on the bottom edge of the last white mark before the letter 'E'. I ran till the needle just touched the 'peg' and the truck finally ran out of gas 6 to 8 miles later. (Again I was towing an enclosed car trailer and the overhead avg MPG was showing 11. 7 and quit 43 actual miles past DTE of 0).
-Each time I topped the tank to the vent hole the 'DTE' would stay the same value for many miles (I guess the computer will not (cannot) account for fuel beyond 'full' indication). So I disregard it till it starts to click down.
-The 'low fuel' light/chime came on some distance before 'DTE' was zero but I did not record at what value.
-When I reset all the overhead computer values prior to the last last leg of this test... I noticed that the DTE value dropped (I was towing in part stop & go traffic) from when I first noted the distance.
Specifically when I started on the last leg the DTE said 95 miles... But when the DTE finally indicated 0... I had only driven 75 miles.
-I have filled at the big rig docks using the 'large' pump nozzle but have yet to fill completely at the very high rate these things put out. (I think there are just 2 sizes of these pump nozzles). So I'm not sure how much the fuel foams when using that nozzle type. Don't want it to spill out on my truck!
35. 5 gal - when the fuel pump nozzle 'clicked' off.
41. 4 gal - when I saw the fuel level on the bottom edge of the vent hole inside the neck (after spending 6 to 8 min slowly filling the tank).
Here are the facts:
*Outside temps avg 75 degrees/and using 'summer' diesel fuel.
*Ran the truck till it surged (and finally quit running as I pulled over).
*The truck was on a straight and level road at this moment.
*Added 4. 0 gal of fuel.
*Started the engine per the owners manual for an empty fuel filter (several turns of the starter, then released the key to 'run' while the lift pump continued to run. Then turned the key back to 'start' - it started after 3 revolutions from the starter).
*Reset the overhead computer 'avg MPG' and 'distance'.
*Drove 10. 0 miles to the nearest gas station that sold diesel.
*The truck was on level ground when being refueled at the pump.
*The overhead computer showed 10. 5MPG for that part (I was towing an enclosed car trailer).
*the pump nozzle at this station is the 'smaller' type on the 'auto' diesel pumps - not the large one found at the big rig docks.
*I filled the tank running the nozzle almost continuously untill the pump showed 28 gal - pausing and slowly pumped to 30. 5 gal (wanted to see when the gage needle showed 'Full' (I think the gage still laged - and the nozzle still had not 'clicked off').
*Continuously ran the pump at a high rate from 30. 5 to when it finally 'clicked off' - 32. 8 gallons indicated on pump.
*Continued to fill tank till the fuel level was at the bottom of the vent tube hole in the filler neck - 38. 7 gallons indicated on the pump.
Conclusions that I draw:
-with my short drive to the station I estimate that I used 1. 3 gallons: the fuel used in the actual drive and the fuel the lift pump put into the fuel filter when it ran a short while prior to start. (at least I think thats what it was doing). So that left 2. 7 gal left in the tank when I started to pump in the fuel.
-amount of 'usuable' fuel in the tank when the nozzle clicked off: 32. 8 + 2. 7 = 35. 5 gallons.
-amount of 'usuable fuel in the tank when the level was sighted at the bottom of the vent tube opening in the neck: 38. 7 + 2. 7 = 41. 4 gallons.
-Had I not slowed the fueling process near the end I think there would have been more foam to maybe cause the nozzle to click off earlier... maybe just over 35 gal total usuable fuel. Previous times in refueling I seem to add 5. 5 gal but mostly 6 gal of fuel when filling to the vent line hole in the neck... so this may not be the case after all.
Other Notes:
-When the 'DTE' on the overhead computer showed 0 (and it stayed on 0) I was able to drive another 43 miles from that point till the truck finally ran out of fuel. (BTW the DTE was probably reflecting my avg MPG of 11. 7 the previous 120 miles of driving part stop and go city driving and part highway).
-I had topped off the tank previously to the vent hole in the neck... and driven 511 miles when the fuel gage needle was just above the last white mark in front of the "E"... between 1/16 and 0 on the gage. (all but 220 miles of this was pulling my enclosed car trailer). When the DTE showed 0 the gage needle was on the bottom edge of the last white mark before the letter 'E'. I ran till the needle just touched the 'peg' and the truck finally ran out of gas 6 to 8 miles later. (Again I was towing an enclosed car trailer and the overhead avg MPG was showing 11. 7 and quit 43 actual miles past DTE of 0).
-Each time I topped the tank to the vent hole the 'DTE' would stay the same value for many miles (I guess the computer will not (cannot) account for fuel beyond 'full' indication). So I disregard it till it starts to click down.
-The 'low fuel' light/chime came on some distance before 'DTE' was zero but I did not record at what value.
-When I reset all the overhead computer values prior to the last last leg of this test... I noticed that the DTE value dropped (I was towing in part stop & go traffic) from when I first noted the distance.
Specifically when I started on the last leg the DTE said 95 miles... But when the DTE finally indicated 0... I had only driven 75 miles.
-I have filled at the big rig docks using the 'large' pump nozzle but have yet to fill completely at the very high rate these things put out. (I think there are just 2 sizes of these pump nozzles). So I'm not sure how much the fuel foams when using that nozzle type. Don't want it to spill out on my truck!
