True Gas Tank Capacity

Discussion in 'Dyna Models' started by Hoople, Aug 18, 2009.

  1. Hoople

    Hoople Account Removed

    I have a New 2009 Dyna Low Rider and had a question about true gas tank capacity. The owners manual states the fuel tank capacity is 4.8 US gallons. I can ride until the physical needle on the gas gauge is at the bottom of the red bar. Along with that, the digital display readout says r6 meaning I have 6 miles left on reserve.
    Now I can pull into a gas station and can only put in 3.8 gallons. Not a drop more. Were did the entire extra gallon go. Is this normal?

    Tks! Hoople
  2. sanec1

    sanec1 Active Member

    Welcome to the forum. I've posted a similar question. I'm not concerned with gas mileage, more with how far I can go on a tank of gas. The gauge is more of a guide than anything. I have an inch and a half of gas left when the reserve light comes on. Try a search using "gas consumption" or "mileage" and see what comes up. I'm thinking of gassing up, taking some spare gas with me and see how far I go with a full tank.
  3. Hoople

    Hoople Account Removed

    I was thinking of doing the same thing about bringing along a gas can. I could understand a difference of maybe a quart or so but a gallon is a lot.
    When my reserve says I have only 6 miles to go till empty, I actually have a Gallon of gas in the tank. Made no sense to me.
    I like the idea of bringing along some gas for a ride!


    GOING UP Banned

    The extra gallon of fuel is still in your tank, dont trust your gauge or the digital readout, if you can go 150-175 miles on that 3.8 gallons do it, and then fill up.
  5. wildey

    wildey Active Member

    I have an 08 ultra with a 6 gallon. Same issues, gauge dead on empty, miles to go no longer showing and it only takes 4.8 gallons I think once it took 5.

    I look in the tank and can't see anything except the filter, pump etc. I swear Im just going to drain the tank next time and see how much is really left.

    I have thought about carrying a gallon too and doing it that way but I think I would feel more comfortable in the pole barn at home
  6. Hoople

    Hoople Account Removed

    My guess would be since this bike is FI and the pump is in the tank, it must have at least a gallon to cover the pump so it wont suck air..Maybe the fuel cools the electric motor so some has to be in it?? I don't know just a wild guess. At the same time you would think the owners manual would say something about it. By reading the manual, you think you have near 5 gallons and you may not. Going to do the "ride with a gallon thing" and post results.
    Unless of course someone knows the real answer!:)
  7. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    The light and/or readout are just reminders. They are NOT precision instruments.

    You guys might want to do it as an experiment so you really know. Next time you get the "light" or the readout, pick up your gallon tank of gas (with a know quantity in it!!) and continue running around until you completely run out. Don't do this riding at 75 mph in the fast lane!! Some path less traveled is better.

    Put the known amount in and go straight to the gas station. Top the tank off to the point where it is running out the overflow. Add the two quantities. That is your real capacity. Divide the trip odometer by the total you put in the tank. That is your average fuel mileage (at least on that run). Subtract 30 from the reading on the trip odometer. This is the absolute number of miles that you can run before you MUST find a station. Adjust these numbers over time based on what you learn in collecting data on number of miles vs. gas used to fill tank. Reset your trip odometer each time and keep a log.

  8. cyborg

    cyborg Active Member

    My 09 Super Glide gauge is the same way, on empty with still a gallon in the tank. BUT i would rather it be that way then the gauge on 1/8 of a tank and out of gas along the road.
  9. Mdbtyhtr

    Mdbtyhtr Member

    Electric fuel pumps must be submerged to keep them from overheating. It is the same for your car or truck. I would not want to run too low as it will effect the longevity of the pupm. Another thing, lean = Heat, if you were to run low and the fuel pump can't deliver the proper fuel volume/pressure, your injectors won't fire properly and you could burn a piston.

  10. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

    Also, running a fuel pump dry means it may damage internal seals because the fuel is a form of lubrication, and you may lose "prime", causing air cavitation and have a hard time starting up the pump again. Add to it all the "tank debris" flowing in there as well may get pumped through the system fouling the works. TQ is not being conservative when he says 30 miles...JMHO, been in some areas where it was like 50 miles (1 gallon typical) needed just in case...lose a "last gas" sign and your in trouble.