Diesel vs. Gas engines on ZTRs

Discussion in 'Lawn Mowing' started by gbparn, May 4, 2011.

  1. SouthSide Cutter

    SouthSide Cutter LawnSite Bronze Member
    Messages: 1,331

    Got some friends one bought a 997 and the other bought a TT. And the 997 ruts worse than the TT. And my TT ruts worse than my TC, I just think the diesels are over kill for most lawns.
  2. 4 seasons lawn&land

    4 seasons lawn&land LawnSite Gold Member
    from NY
    Messages: 3,613

    I would consider a diesel on a 72". Nothing smaller. Even the 72 would be border line/on the fence. Some of those smaller diesels out there actually cant compete with the big 30+ hp gassers. No experience to back that up, just what I have heard.
  3. ClassicLawnCareInc

    ClassicLawnCareInc LawnSite Senior Member
    Messages: 745

    One could argue that the diesel is over kill, I personally always say its better to have some extra or reserve power than to run at max all the time.

    On the smaller diesels like my 2 hustlers it has 25 hp and it does a great job for small lawns. It has plenty of power, its a smaller machine and cuts better than my gas mowers.
  4. blowerman

    blowerman LawnSite Member
    Messages: 70

    Odd to give an opinion if you don't have experience... To say "Some of those smaller diesels out there actually cant compete with the big 30+ hp gassers."
    While some might be true, my own experience we added a 25hp kubota diesel in a TT and have found our fuel usage savings of over 1 gal. per hour and power is equal if not better than our 30hp. + gas motors.

    Minus the weight issue, the change over to diesel is well worth it!
    That's my opinion with field data to back up my reasons!
  5. Mark Oomkes

    Mark Oomkes LawnSite Fanatic
    Messages: 15,290

    First off, find a new small engine guy. I wouldn't let this guy work on a tricycle. What an idiot.

    If money isn't an object, go with the diesel, you'll be thrilled that you did.

    Can't answer the ethanol questions.

    Have you ever run a 72"?

    Or a diesel?

    Can't compete? On fuel usage, true enough, you'll be going through gas much quicker on a 30+ HP gas than a diesel. And be able to cut more grass, and taller\thicker.

    As an aside, you might either want to listen to other people or just stop listening.

    P-shaw, field data? My brother's uncle's cousin's sister's niece's nephew's grandma said gas was better.

    I can't give actual gallons, but close. First Lazer we bought was a liquid cooled. On a long day or a lot of grass, we'd have to switch tanks sometime in the afternoon and use about half the second tank. Got an air-cooled for a demo once and ran out before noon on the first tank. The diesels I have now (Daihatsu crap) will run one tank dry a couple times a year. Barely.

    If I could get diesels on my WB's I would.

    Normal maintenance is no different than a gasser. Long term--on my Daihatsu's--I was screwed. They are crap, which explains why Exmark doesn't use them anymore. Still wouldn't keep me from buying another diesel Z.
  6. gbparn

    gbparn LawnSite Member
    from TS, TN
    Messages: 7

    I didn't say he was MY small engine guy. It was a small engine shop I came across in my travels trying to find a dealer who has a Ferris 2500 on the floor.

    Concensus here is that a bigger gas engine does not outperform a diesel engine and the torque comment is bovine scat.

    Someone in this thread mentioned they had a fuel injected gas engines? Which brands are using fuel injection? Will the fuel injection reduce some of the fuel issues that are caused by ethanol?
    Are the engines in commercial mowers big enough that they really aren't having much issue with ethanol. Or is it the trimmers, saws and older boat motors the ones having the ethanol problems.

    I have a JD 737 and have had problems with the 24hp Kawi on it. JD service tells me that some of the engine issues that mower is having are related to ethanol. I think its also related to bad design too.
  7. 4 seasons lawn&land

    4 seasons lawn&land LawnSite Gold Member
    from NY
    Messages: 3,613

    uh that would be the reason for the second sentence. Can you read?
  8. Mark Oomkes

    Mark Oomkes LawnSite Fanatic
    Messages: 15,290

    No, but he can hear.
  9. TWerner

    TWerner LawnSite Member
    Messages: 80

    Huge Diesel Fan here. Even if it were just because they sound so much cooler when you first start them up.

    The biggest plus for the diesel's isn't so much that it makes more torque, but that their torque curve is much flatter. If you always run your gas engine at full throttle and never lose any RPM's, then the diesel won't benefit you much from a power point of view, but it will save you a LOT of gas. Partly because they burn less at WOT, but also because you won't have to run WOT all the time. You'll have plenty of power at 70%.

    If you're running more than 30 gallons of gas through your mower a week, and a diesel will take 15 gallons, how long does it take for a more durable engine that's saving you $250 a month in gas to pay for itself? Probably not long in Florida, but might be a while in Vermont with the shorter mowing season.

  10. bamaturf

    bamaturf LawnSite Member
    from alabama
    Messages: 136

    i run gas & diesel. 25 kaw over 1 gal per hour likes gas
    26 efi kohler 1 gal per hour
    26 kubota diesel .63 gal per hour 9.5 gal into 15 hrs
    bx 26 kubota tractor .52 gal per hr 3.4 gal into 6.5 hrs
    this tractor was a rental for sat , moving topsoil & digging up stumps, has the
    same 26 hp diesel as my zd326. amazed at the fuel mileage. most of the time
    we run off road diesel @ 20 cents a gal cheaper than regular diesel

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