Diesel vs. Gas engines on ZTRs

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

  1. DLCS

    DLCS LawnSite Platinum Member
    Messages: 4,386

    I have gassers and I have a diesel. My diesel is a JD 997 w/72" deck. The 997 burns 1/4-1/3 a gallon per hour. I had a 850a with a 72" before the 997 and the 31hp Kawasaki burned almost 2 gallons per hour. The extra cost of the diesel will pay for itself quickly with todays gas and fuel prices. I don't see how you guys who run these big block gassers can justify them over long term with todays fuel prices. Diesel is a better option today. I need to replace my 757's next year, i'm hoping Deere comes out with a smaller diesel in a small frame ztr, you listening Deere? BTW, i didn't buy a diesel for horsepower or torque. I bought it for fuel savings and longitivity.

    KINGMADE LawnSite Member
    Messages: 237

    Sounds like your small engine guy does not like to work on diesels. Diesel motor will out torque the gas one all day.
  3. luckylawnboy

    luckylawnboy LawnSite Senior Member
    Messages: 433

    I ran a ferris with the 3 cylinder 31 0r 33hp cat diesel is 5100. It was a useless piece of crap. Blade tip speed would drop just from from driving the machine. When cutting it would only mow at half speed if that in heavy grass. I loved the ride but the machine was way under powered. It needs a turbo in my opinion. I would like to try the Dixie Chopper or Bad boy as they use a 4 cylinder cat engine. I just dont understand why they are not putting turbos on these small diesel engines?

    My z 970 with 37 hp gets 1.8gph but it cuts twice as fast as that ferris plus I paying a guy twice the labor if I buy a diesel. Dixie Chopper had a turbo Diesel that was 50hp but that mower was out dated.
  4. Mark Oomkes

    Mark Oomkes LawnSite Fanatic
    Messages: 15,290

    They do, Kubota has a couple models in Toros that have turbos.

    IIRC, that is the same model Ferris I demoed and it had plenty of power as well as the great ride. Just didn't like the cut quality.
  5. Tall Rider

    Tall Rider LawnSite Member
    Messages: 118

    Ok to add another monkey in the barrel right now lets throw another problem into the mix. Right now where I live diesel is $4.39 a gallon. Now couple that to the added cost of the machine and is having the diesel ZTR really more efficient or better right now in todays market? I take into consideration what type of use these machines would work in, heavy commercial or industrial and all I here about on here is how cheap that area of work is going for now. Normally in better times with cheaper fuel prices this is how these other company's could afford to bid these larger properties so cheap. Right now I don't see any added benefit of the diesel and the weight of one around here would rut something fierce. Does anyone know what a 2011 Toro 590D in a 60" or 72" goes for now? I remember they were close to 17K or 18K before and no one around here knows anything about Daihatsu engines. Anyone run one?
  6. Mark Oomkes

    Mark Oomkes LawnSite Fanatic
    Messages: 15,290

    Doesn't matter, run from the Daihatsu's as fast and as far as you can. They are the biggest POS engine's I have ever had the displeasure and expense of owning.

    Worse than a Ford 6.0, and I have 3 of those.

    Guaranteed within 1500 hours they will need a rebuild. Either the head will crack or oil consumption will be through the roof.

    There's a reason Exmark stopped using these boat anchors and bit the bullet and are using Kubotas now.
  7. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    The biggest issue with diesel power is weight. This is true in light trucks, and in ZTR's.

    A Kohler V-Twin weighs in just under 100lbs dry.

    A.... (lets use Kubota) 3cyl 1L Diesel is over 200lbs dry. Now add 3 more quarts of oil, a radiator, hoses, fans, and coolant.

    Adding 2-300lbs to a 1300lb ZTR is a BIG deal.

    Especially when we have some rather excellent air cooled V-Twins these days.

    This Kubota Diesel is 25hp and ~45lb/ft of torque. You can get a gas powered V-Twin that will blow it's doors off when it comes to power and RPM maintaining torque.

    ZTR quality continues to improve, but for the most part, a ZTR is pretty worn out after 3K hours, no sense putting a 10K hour engine on a 3Khr ZTR. Especially when the diesel is adding thousands to the MSRP.

    I'd love to have a little 1L diesel that's TURBO'd to keep torque up and maintain RPM's better. Don't know why manufactures dont explore this a little further.
  8. TWerner

    TWerner LawnSite Member
    Messages: 80

    Cost! A small turbo would add more cost than a few extra cc's of displacement.

    You make a lot of good points on weight, and on the engine outliving the frame. My experience with diesel engines is in tractors, and weight is not an issue there. In fact, my Kubota was a bit light.

    I don't have enough info to crunch the numbers, but if a diesel uses 65% of the GPH, what is the fuel savings/season for a busy LCO. I'd think there would be much bigger savings on LCO's that manage huge properties where you put a lot of hours on the machine, and wouldn't spend a lot of hours carting a heavier mower around.

    Fuel savings would seem to be the biggest benefit to a diesel. Plus they sound better than a gas engine LOL
  9. Mark Oomkes

    Mark Oomkes LawnSite Fanatic
    Messages: 15,290

    Toro already has a 4WS and a Z with the Kubota turbo diesel. 32 or 33 HP something like that.

    As for longevity, yes I figured that into it as well, but I think (if Daihatsu's weren't crap) that it would have paid off for me, and we don't mow as much as a lot of members.

    Also, I wouldn't compare the weight of an air-cooled to a diesel, in fact, based on my experiences, I would never buy an air-cooled mower if a L\C is available, strictly due to fuel usage.
  10. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    I used L/C'd on several occasions over the past 30 years, and each time I had issues with coolant leaks, water pump leaking, hoses, etc.

    As a blanket statement, unless a L/C'd version offered something an A/C'd didn't, I'd stick with A/C'd.

    For instance, back in 2001, you couldn't get a ZTR with more than 25hp. Lazer offered the L/C'd Kawi and it was 27hp....I bought it for the 2hp....sold it for the complexity and leaks.

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