Gas verses Diesel Large Commercial ZTR

JLH52

LawnSite Member
Several questions about diesel ZTR's. I've never owned or operated a diesel ZTR, gas only.

Currently I own a 72 in. Hustler Super Z Hyperdrive 37 hp. Vangard Big Block EFI. I like everything about the mower, except maybe the noise. Hydro is smooth as butter, flex forks plus Grammer 65/531 with fore and aft isolater make for a smooth ride. 37 hp. EFI has plenty of power.

Hustler offers a Shibaura 25 hp. diesel only.

* Would the power and ability of the diesel be better, worse or equivalent to my current mower?
* Would the diesel be more or less fuel efficient ?
* Would the diesel be quieter than the gas?

From your experience with diesel and gas what are the pros and cons? Which do you prefer and why?
 

Ridin' Green

LawnSite Fanatic
Location
Michigan
The engine you have will easily out power that diesel ( and I am a big diesel fan). The diesel will have more smell to it, and IME, be louder, though not that much. It will be better on fuel and should theoretically last longer, and in your situation, those are about its only advantage between those two engines.
 

Mowing monkey.

LawnSite Bronze Member
I’ve got a Grasshopper with a 28 hp Kubota diesel with a 72”. The power output is plenty. It’ll burn the belts off if that’s what you want to do. The noise is less than a gas burner. The lifespan is much longer than a gasser. The Kubota diesels will run upwards of 10,000 hours. The fuel consumption is much better than the gas burner. Like less than half the fuel burned. I’m burning around .5 gph running at full throttle. I’m guessing your Vanguard is burning 1.5 gph.
 
OP
J

JLH52

LawnSite Member
I’ve got a Grasshopper with a 28 hp Kubota diesel with a 72”. The power output is plenty. It’ll burn the belts off if that’s what you want to do. The noise is less than a gas burner. The lifespan is much longer than a gasser. The Kubota diesels will run upwards of 10,000 hours. The fuel consumption is much better than the gas burner. Like less than half the fuel burned. I’m burning around .5 gph running at full throttle. I’m guessing your Vanguard is burning 1.5 gph.
I'm burning 1.3 gal. per hr.
 

Diesel Dude

LawnSite Member
I’ve never ran the Shibaura diesels, but I think they’re a good motor. I’ve ran both gas and diesel, and I prefer diesel over gas. In your particular set up I’d say that 25 horse diesel would be underpowered. Especially compared to that 37 efi motor.
I would say that the diesel would be more efficient on fuel. From my experience diesels are a little quieter and when rapped out full throutle they are extremely smooth.
I’d probably stick with what you have.
When I was looking at hustler they didn’t offer the hyper drive with the diesel option. Are they now offering that option? I think between the 72” deck and the hyperdrive system it’s going to really put that little 25 horse on its face. Maybe I’m wrong but From my understanding the hyperdrive takes more power to run.
 

Shindaiwa_operator

LawnSite Member
Location
Paxton, NE
I’ve never ran the Shibaura diesels, but I think they’re a good motor. I’ve ran both gas and diesel, and I prefer diesel over gas. In your particular set up I’d say that 25 horse diesel would be underpowered. Especially compared to that 37 efi motor.
I would say that the diesel would be more efficient on fuel. From my experience diesels are a little quieter and when rapped out full throutle they are extremely smooth.
I’d probably stick with what you have.
When I was looking at hustler they didn’t offer the hyper drive with the diesel option. Are they now offering that option? I think between the 72” deck and the hyperdrive system it’s going to really put that little 25 horse on its face. Maybe I’m wrong but From my understanding the hyperdrive takes more power to run.
Can’t take more power than the standard Super Z without hyperdrive! Those hydro sap power like nothing else, makes our 33hp Kohler feel like 23hp.
 

CGros31

LawnSite Bronze Member
In that situation, the 25 HP diesel will be wayyy weaker than the Vanguard. I run a couple of diesel ZTR’s. They are much more fuel efficient, quieter at full throttle, and are expected to have a much longer engine life. Diesel mowers upwards of 30 HP would hang with the Vanguard however.
 

AlohaMowing

LawnSite Senior Member
Location
Hilo, HI
The diesel would probably have torque to compensate for lesser horsepower. But . . .

When I was shopping for a new TT2 I contemplated the Kubota diesel version. It would have simplified my fuel storage, but I decided against it because of the extra cost of the diesel model compared to the liquid cooled Kawasaki, and because I think the diesel engine would be too good, i.e., it would be in the prime of its life cycle when the rest of the mower was ready to be scrapped. Doing rural mowing in a humid (rust inducing) area I may be harder than most people on my equipment and a diesel could make sense for some people.
 

Mowing monkey.

LawnSite Bronze Member
I think you’d still come out ahead in the long run with the Kubota diesel vs Kawasaki. The gas burner is good for 1-2000 hours. The hydraulics on the Kubota is good for minimum 3000 hours. So you saved money up front but you’ve spent more money every day for fuel and probably a motor replacement.
 
Top