Diesel Super Z

Discussion in 'Hustler Turf Equip (Archived)' started by Tonyr, Oct 22, 2003.

  1. Tonyr

    Tonyr LawnSite Bronze Member
    Messages: 1,973

    Hi Pj,

    Have you got any photos if what next year's new diesel super z will look like?

    I heard it will be 28hp, just for interest sake, can I ask, Wich engine out of the diesel 28hp and the Kohler 28 efi has the most power?

    I want to do long heavy work with a 72 inch deck, what engine will power this size deck the best in very heavy work?

    What confuses me is, I have a Toyota 4 x 4 landcruiser diesel, gutless but good on feul, drive the same size motor in petrol no comparison, gas has tons more grunt.

    Wandering then, if the same comparison applies in mowers, the gas model has the most power for hard mowing, only the diesels are built to work hard but lack the power of petrol, diesel I think is just a feul saver and longer living engine, but lacks power compared to the same engine size petrol.

    I guess the diesel would not stall as quick in thick stuff, just tries to power through at lower revs...?

    Your feedback and comments are appreciated, I'm confused with this subject...

    I hope you have pics of the diesel super Z, keen to see if the machine has much more rear overhang.

  2. mowerconsultant

    mowerconsultant LawnSite Fanatic
    Male, from Syracuse, NY
    Messages: 9,769

    We are working on a diesel.
    We are looking to go into production next summer.
    As far as engine and other spec's and info, I can not elaborate at this time.
    All I can say right now is that this mower will be the diesel mower of choice and coupled with the Super Z, it will be a very, very, productive mowing machine !!!

    We will let everyone here at LS know when we have more info.

  3. MacLawnCo

    MacLawnCo LawnSite Bronze Member
    Messages: 1,847


    DC is right on your heals, as im sure you know. Rumor is that they are working on a Kubota diesel too. Tough competition for you is ahead.
  4. J.Gordon

    J.Gordon LawnSite Senior Member
    Messages: 674

    For working, longevity, Torque and fuel consumption I would put a diesel against a gas burner any day. Being the same horsepower.
    My wish would be that Hustler would put a big Diesel on the machine that had the grunt in it to spin the blades fast enough while making redline (Max RPM) 1800 RPM.
    Under 60 H.P. I would prefer the Kubota.
    Just my .02
  5. Tonyr

    Tonyr LawnSite Bronze Member
    Messages: 1,973

    Thanks zip63,

    This is what I'm needing to know, the issue of the diesel able to keep the blades running at top revs in equal to or rougher/harder mowing conditions to the same size hp gas engine.

    My thoughts would be that the diesel would lose revs quicker thus lose blade speed thus not cut so good unless you slowed right down for the diesel to pick it's revs up again, so if the diesel engine had max torque at 3/4 revs, you aren't going to get 18500fpm blade speed at this point, so you would work a diesel at slower speeds...as I would imagine blade tip speed would be calculated at top engine revs, not at the rev range where torque is highest...

    I guess same goes for gas, heavy mowing, you must travel at the speed your mower can cut best at...common sense.

    I guess as far as I understand/not understand is the gas would hold revs and blade speed up at top revs more so than the diesel, but in tough stuff where both engines would be roaring away the diesel would perform better, but at a slow blade speed.

    Again I guess it is...where do you want highest blade speed and power, max revs or 3/4 range power but slow blades?

    I'm only trying to understand this, but if I am kinda close to figuring this it means a gas engine would be best, only down side for gas is wears out quicker and costs more on fuel, so if you were leasing a machine every 4 years and doing a min of 4000 hours a gas would be better as you aren't keeping the mower?

    Then again 4000 hours is a lot for a 28 hp gas engine....

    I can see the benefits for diesel, last longer, cheaper to run, but they are heavier, bigger, and their max torque is at lower revs therefor lower blade tip speed at this point.

    I know the gas will fade too, and doesn't have that power at the lower rev to keep everything moving.

    I did a search on the new kubota, surprised to read folks say the 28hp diesel in their new kubota ztr was underpowed with 72 inch deck,this surprised me and this is why I am here typing this long reply, I expected people to be saying quite the opposite.

    Still struggling to see where diesel is better on a mower though if people say they are underpowed, maybe need 35hp diesel?

    trucks, tractors, 4 x 4's, plant equipt.

    Like you said, power at top revs like a gas in a diesel engine would be unbeatable!~

    Public Note: when I say a diesel has most torque at 3/4 revs, this is just an example as it means no power level in this conversation, I do not know what kubota's torque range is, and in no way am I saying a kubota engine has max torque at 3/4 revs, I have no idea and I'm not suggesting this.


  6. excel25

    excel25 LawnSite Senior Member
    Messages: 393

    your blade tip speed can be changed with diff. size pullys. the dieael will not bog down like a gas.
  7. J.Gordon

    J.Gordon LawnSite Senior Member
    Messages: 674

    On the Diesel you want the engine to operate in the torque curve, that is where the power and fuel efficiency is. Diesels make their power at lower Rpm’s than a gas engine. Lets just say at 1500 Rpm’s your torque is 100 ft. lbs. And At 1800 Rpm’s 150 ft. lbs. at 2000 Rpm’s the torque starts dropping back to 100ft.Lbs. But the engine will max out at 3000 Rpm’s but the torque will drop even more.
    So you need to gear the machine so it will turn the blades at the speed you want while it is in the torque curve. When you get in heavy grass the diesel’s governor will kick in and you will feel the raw power of the diesel, where the gas engine will fall on its face. I used to pull a 5’ finish mower with a 14 HP. Diesel and it would cut as fast as you would want to go on the rough terrain. A lot of diesels are de-tuned from the factory so the drive train won’t get destroyed. Just go to any of the diesel forums and see for yourself what these engines are capable of. The fastest pickup is a Cummins diesel (Dodge) at 222.139 Mph. Here is a link if you want to see it.
    If a gas engine were the best alternative the Tractor-trailers would be using them.
    If money weren’t a factor the diesel would be the only way to go. More power better fuel mileage longer life.
    I am by far no expert on engines, but the information is out there so you can make an informed decision yourself.
    Hope this helps.
  8. Tonyr

    Tonyr LawnSite Bronze Member
    Messages: 1,973

    Thanks Jeff,

    great feedback, appreciated!

    Now I just need to find out where these 28 hp kubotas have their torque curve and where they set their rev range at top revs...

    The Hustler Super Z gas 28 hp efi is the mower I look like getting when they arrive in my country soon, Hustler is putting a 28hp kubota diesel in a super z next year, my enquiry was to see which would be the best....I heard the diesel isn't due out until next summer though, bummer...I'd love to see what they look like, a proto type pic or something :)

    I'm still confused about why a very few on this forum who own the new 28hp kubota ztr said they were short on power, and maybe Hustler is using the same engine....perhaps just not enough feedback to get a general response about this size diesel in a ztr...
  9. crazygator

    crazygator LawnSite Bronze Member
    Messages: 1,048

    I am sorry but you cant be serious? DC has nothing that can touch Hustler! And everyday that goes by Hustler gets better and better, but DC gets farther and farther behind. Plus all the dealers are being dropped or quitting DC. Wonder why?

    Hustler makes some awesome equipment for us and will continue to set the lead in some new areas very very soon. I look forward to the days ahead!
  10. mowerconsultant

    mowerconsultant LawnSite Fanatic
    Male, from Syracuse, NY
    Messages: 9,769

    I think you have some bad info.
    We have not let anyone know what engine we are using yet.


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