Community Forums

Nonnaof Two · 11-02-2016, 02:04 PM

I wanted to know in case of emergency how much fuel I have once I hit empty.
At the end of our trip heading into town stopped and fueled up. I have a 90 gallon tank. The most I could get in it was 74 gallons. Can someone explain this to me? Did Fleetwood do this to make it dummy proof so you don't run out of fuel or do I have a problem? Another reason I ask, toward the end of a 6-7-8 hour day on the road we smell Diesel exhaust. Like to hear any thoughts.
Thanks
2014 Fleetwood Excursion 33A

nukerj · 11-02-2016, 02:26 PM

Empty on a tank is not truly empty - manufacturers tend to leave some space in the tank. Both for those that like to live on the edge, and because you can't ever truly run a tank dry. The pickup will always need at least an inch of fuel in the tank to work properly. Plus if you have a 90 gal tank, that's full capacity, but you can never fill it all the way up unless its sitting perfectly level or on a slight grade dowhnhill from the filler neck.

Diesel performance shops make a pickup puck, if you want every last bit out of the tank, you cut a hole in the bottom and put in the fuel puck and then you can run it empty, but you would need some sort of sump system as well to prevent fuel starvation from sloshing.

RayJr · 11-02-2016, 02:38 PM

Cut a hole in the bottom??? What? Seriously? OK my Journey on a Freightliner with a Cat C7 that has a 90 Gal tank. I really don't want to take the chance of running out of fuel so when it hits the yellow it's time to stop and most of the time it takes 65-70 gals. A diesel isn't like a gas engine, air in the fuel lines of this unit is/are a bitch to get out. There is no lift pump just the Huei fuel system to pull fule from the tank. So unless you know and have more experience then I do "it aint broke so don't try and fix it" simple.

**Lt Dan** · 11-02-2016, 09:30 PM

When you say it hit empty, did the low fuel warning come on? If so, that's probably about right. I have a 100 gallon tank and the one time the low fuel warning came on, it took 80 gallons to fill up. That was the last leg of a trip and I didn't want to stop and fuel. I normally start looking for fuel when it gets just below 1/2 tank.

Cat320 · 11-03-2016, 06:19 PM

All needle gauges are very unreliable. The best way to plan for fuel usage is to know your approximate MPG and monitor the miles traveled. Do the math and you'll know how much fuel you have remaining.

jelag · 11-03-2016, 09:55 PM

On most modern coaches the fuel level indicator in the tank sends a signal to the engine ECM and its the interpretation of that signal as to what is seen on the dash and when the low fuel light goes on.... one important factor is that a diesel will not prime like a gasoline engine and often there is a mechanical pump, like a small tire pump located on the engine... or secondary fuel filter for priming the engine if you run out....

I suggest that if you wish to experiment with this... you find and understand the process.... on the CAT I own... its on the secondary filter and is also used to prime the engine when the filters are changed... but its always a dirty nasty process... I'd never want to do this on the road after dumping fuel in the tank....

Often the tanks are rated a what is called liquid capacity but you can't really put that much fuel in the tank... they allow for 5-8% of expansion from fuel that is in the ground at 40*F and now your driving at 100*F.... that expansion has to have room in the tank or you have a spill on the ground... something that's a no-no...

Hope this helps..

JumboJet · 11-04-2016, 08:54 AM

Quote:

Originally Posted by Lt Dan

I normally start looking for fuel when it gets just below 1/2 tank.

X2!

Darwin · 11-04-2016, 02:58 PM

I ran my 90 gal tank down to almost empty on the gauge , 73 gal filled up

**JohnRR** · 11-04-2016, 03:16 PM

I'm one who has always let the fuel gauge get low, really low but not so much with the bus I've learned to leave more of a safety margin so if the place I'm trying to get gas does not pass muster for me and the toad I can move on to someplace else that does.

ga traveler · 11-04-2016, 03:41 PM

The answer lies in the fuel gauge. Fuel gauges are iffy at best. 90 gallons is the usable fuel on level ground. Most manufacturers have the gauge read low to keep the owners from running out of fuel. When talking about usable fuel, The tanks are all the same (For that model.) the pickups are all the same. (for that model) the one variable is the gauge. Gauges and senders are just not that precise. This does not hold true for the Boeing 767, but they cost a hundred million dollars and Boeing can afford better gauges.

chuckftboy · 11-04-2016, 04:48 PM

My last trip , the low fuel warning came on, I then drove 30 more miles and filled up. It took 76 gallons. My tank is also 90 gallons. When my needle is on empty, I have about 20 gallons left.