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Community Alumni's avatar
Community Alumni
Sep 02, 2016

Diesel or LP generator

Looking at the options on a new RV and the Onan QG 3600 LP is listed as standard and the QD 3200 (Diesel) is the option. I have not been able to pin down the cost, but it's got to be 3 or 4 thousand dollars more. The dealers are vague on the details. I currently have a QD 3200. I have read the pros and cons of each fuel and the overall cost of operation. In six years, it has only accumulated 185 hours. I have no idea how that compares to the average RV generator.

Here is how I use it: When parked en-route, I will run the generator for the AC. Generally, there is always power at our destination. Noise restrictions limit the use just about everywhere. I have the RV generator and my house set up for emergency power and the only time I had it connected was to test the setup. Of course, the electricity has never gone out in the six years I have had this arrangement. Any other demand such as charging the batteries does not load the generator enough.

Not sure if staying with Diesel is worth the extra initial cost. All I know that when we were stuck in a blizzard overnight, the Diesel started right up an kept us going. A friend had a LP generator and all I hear from him was how hard it was to start.

16 Replies

  • Community Alumni's avatar
    Community Alumni
    Dakzuki makes a good point. The only thing that is not vague is the final cost. Especially lost in the shuffle is what you actually get for the trade-in and what you are really paying for on the new unit.

    Let's say 'The Big One' hits and the power goes down. That is, the Mega Quake. It will be easier to shuttle diesel to fill the tank than it would be to get propane. I can power my house with the generator, assuming that there is still a house. But then, I could be an RV full-timer. The odd thing about the diesel generator I have now is that it does not have full access to the fuel in the tank. The tank is about 26 gallons. When the fuel gauge reaches zero and the warning light comes on, there is about 6 gallons left. I know about how far I can go before I have to walk. However, the generator runs out of fuel at about 1/4th tank on the gauge. That means there is a lot of fuel that can't be used. One of Murphy's Laws says that the likelihood of disaster striking is inversely proportional to how prepared you are.

    I have thought about a small inverter generator for just keeping the lights on and the battery charged when dry camping. Space is limited and then there is having to carry gasoline.

    I just think I sold myself on getting the optional solar panels. About 100 Watts. There is a 1,000 Watt inverter installed, so there is that.
  • Sounds like time for another dealer if they cannot provide you a price.
  • Your diesel fuel tank is much larger than your LP tank, particularly when you take into account the fact that diesel provides a good bit more potential energy per unit volume than LP.

    For the amount you use the generator, I agree that the difference in initial cost would seem to make the LP generator the logical choice if you can manage with its fuel usage. It might also be sensible to instead carry a portable generator, though that's less convenient to use and yet another fuel to deal with.
  • Teacher's Pet wrote:
    On board LP tanks can run out and diesel tanks can reach the 1/4 tank level shutting down the generator. That said it's easier to find diesel on the road, diesel can be added from containers at one's home in an emergency. Propane requires a trip to a bulk tank or a visit from a supplier if at home, if they will fill it, neither source is as readily available as diesel fuel.


    X2
  • Biggest plus for the diesel is amount of fuel needed to keep it running. They are very fuel efficient compared to a LP generator. With number of hours yours has run. It would not warrant switching to Diesel.
  • On board LP tanks can run out and diesel tanks can reach the 1/4 tank level shutting down the generator. That said it's easier to find diesel on the road, diesel can be added from containers at one's home in an emergency. Propane requires a trip to a bulk tank or a visit from a supplier if at home, if they will fill it, neither source is as readily available as diesel fuel.