Diesel mowers use 1 gallon per hour?

Discussion in 'Lawn Mowing' started by Envy Lawn Service, Nov 28, 2004.

  1. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    I've been meaning to post this question since returning from the Green Industry Expo. I asked eXmark, Grasshopper, Gravely, ect about their diesel powered 60" class mower's fuel consumption and all of them told me "one gallon per hour under normal operating conditions."

    This is reguarding the 27hp Briggs diesels and the 21 & 22hp Kubota diesels.
    Since when did these small diesel engines start consuming so much fuel?

    Are they mistaken? Playing it safe? Or do I have a bad memory? I don't recall my 3 cyl diesel tractor ever using that much fuel back when I had it. Best I remember I had a 5 gallon transport can to use when needed and that was plenty to run all day on.

  2. weve

    weve LawnSite Senior Member
    Male, from Central Illinois
    Messages: 385

    I just checked my diesel fuel purchased and hours run this year and the fuel usage comes out to right at one gallon per hour. I have a Dixie Chopper with the Yanmar diesel, a 60 inch deck plus the FlexDeck. I use the FlexDeck about 40% of the time. I've been running diesel for five years now using from .9 to 1 gallon per hour. On my last gasoline powered unit with 25 hp Kohler engine, I used 1.45 gallons per hour.
  3. Travis Followell

    Travis Followell LawnSite Silver Member
    from KY
    Messages: 2,206

    I can't believe a diesel engine burns 1 gallon an hour. Those 29 hp LC DFI Kawasaki's only burn 0.8 gal/hr under load. I would have thought a diesel would burn less than that.
  4. steinerguy

    steinerguy LawnSite Member
    Messages: 63

    I have a Steiner with a 60" deck and certainly do not use a gallon an hour. I hold 6 gallons and use more like 1/2 gallon an hour. After 5 to 6 hrs of mowing, I can get 2 or so gallons in the tank. This is a D600 Kubota at about 18 hp. It works hard but does very well with a large mower and deck.
  5. Mowingman

    Mowingman LawnSite Platinum Member
    from Texas
    Messages: 4,720

    Grasshopper 28HP Kubota diesel/72" deck: 0.5 GPH in average conditions
    0.75 GPH in heavy conditions
    Grasshopper 21HP Kubota diesel/61" deck: 0.5 GHP average conditions
    0.75 - 1.0 GPH heavy " "

    These numbers were from over two years of running these machines, and keeping records.
  6. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    Thanks everyone. I was beginning to think I had lost my mind.... I didn't thnk those little diesels used that much. I was even told the newer engines that are supposed to be even more fuel efficent used 1 gallon per hour.


    Speaking of those more efficient engines.... what do you think of that new 322D Max Torque?
  7. out4now

    out4now LawnSite Bronze Member
    from AZ
    Messages: 1,796

    The Deere mower we had never used that much. Was a 430 model and it's relacement (sorry can't remeber the model#) used even less. 1/2 gallon an hour at the most on the 430 and less on the replacement mower. $30 had a 60 inch mid mount deck and that was cutting at full RPM,s. Alos had a Kubota mower as a loaner occasionally and it was a diesel with a smaller deck and it didn't use that much. What size engine did these mowers have? A gas engine might use a little less than a gallon an hour but not the diesels.
  8. Mowingman

    Mowingman LawnSite Platinum Member
    from Texas
    Messages: 4,720

    I have not had a chance to run one. In fact, the only one I have seen was one at the factory, right before they made them avail. to the dealers.
    Folks who have run them tell me that it is amazing how much more torque they have than the Kubota 21hp engine they have been using. They say you can really tell a difference when you are running a 61" deck in thick mowing conditions.
    I have always thought the old 21hp, with a 61" deck, was fine in routine cutting, but just a little underpowered in heavy conditions.
  9. Flex-Deck

    Flex-Deck LawnSite Silver Member
    Messages: 2,845

    I have a 1988 JD 332 with a 50" main deck and a prototype flexie deck-64" total, and it can not suck more than 2/5 gallons per hr. (5 gallon tank -12 hrs mowing) - it is a 16 HP Yanmar.
    I also have a new 595 - 24 HP yanmar - pulling a 9 1/2 foot swath. It uses about 4/5ths of a gal per hr.
  10. out4now

    out4now LawnSite Bronze Member
    from AZ
    Messages: 1,796

    Flex-deck, have you put a Flex deck on one of the 7 iron decks yet? If so how did it work out? I see that you signed with Dixie for a factory Flex deck option. Are you going to be doing that with other manufaturers or did you have to sign an exclusive contract with them? I gotta admit I had my doubts about it until I saw the pictures you posted of the jobs you're doing. That machine does cut really nice.

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