deck size vs. time in mowing efficiency

[IthacaJeff 151]

Okay, here is the question. . .

WH 416-8 (Kohler 16 hp 341) with a 48" deck versus a Simplicity Sunstar with a 60" deck and Kohler 20M

20 hp Magnum). Which will use less fuel? This may not be a fair comparison given that the Simplicity is a

hydro and using hp just for that. I don't know how fast the Simp can mow as I've not done it yet.

Essentially, the big question boils down to this:

What will use less fuel, using a large engine tractor that can use a larger deck and perhaps a

faster mowing speed to cut down mowing time, or a smaller engine that is more fuel efficient but takes more time because of a smaller deck. Is there a point where small is too small and big is too big (okay

no comments on that one!). Assume about 2-3 ac of relatively straightforward mowing with minimal

trim work.

Experience with this?

Jeff

[Herbl 10]

Hi Jeff

I can tell you from my experience of a WH 520H w/48" deck and a Simplicity Sunstar w 60" deck. The Sunstar used less gas and mowed it quicker, I mow 2 acres with a lot of trees. I do have a 60" deck for the 520H and I will put it on this summer and give you an update but the Kohler is easier on gas than the Onan. The Onan is more powerful but the Kohler M20 still doesn't have any problem with a 60" deck. As far as speeds with the Sunstar you can mow faster as it has a 2 speed (locking) rear, if fact the high speed really moves. I really do like the Sunstar it is very well made but I also like my 520H's I have 3 of them also....

[CRE1992 135]

Jeff, I hope I don't come off in a bad way when I say this, but your going to be mowing your lawn, its not going to make that big of a differnece whether you use 1.5 gallons, 2 gallons, 2.5 gallons, or 3 gallons. It might cost anywhere from 2-8 more a week or everyother week. But with a 60" deck you will be getting done faster, goes to a efficency/time ratio. If you want something that would be better on gas and mow quicker you should of bought a zero turn mower. I understand you got a very good price on that sunstar but either way it is still going to be a lot cheaper than paying some one to mow your lawn. I had a 60" deck on my 520H, and now I sold my 520H to buy a 72" Dixie Chopper zero turn. The dixie mows at 10mph and leaves and excellent cut. However when on a garden tractor anything above 5mph, and it doesn't look so good anymore.

[WheelHorseSteve 56]

Jeff, I hope I don't come off in a bad way when I say this, but your going to be mowing your lawn, its not going to make that big of a differnece whether you use 1.5 gallons, 2 gallons, 2.5 gallons, or 3 gallons. It might cost anywhere from 2-8 more a week or everyother week. But with a 60" deck you will be getting done faster, goes to a efficency/time ratio. If you want something that would be better on gas and mow quicker you should of bought a zero turn mower. I understand you got a very good price on that sunstar but either way it is still going to be a lot cheaper than paying some one to mow your lawn. I had a 60" deck on my 520H, and now I sold my 520H to buy a 72" Dixie Chopper zero turn. The dixie mows at 10mph and leaves and excellent cut. However when on a garden tractor anything above 5mph, and it doesn't look so good anymore.

Well said, Charles! I mow with a Scag w/ 61" deck and the cut speed and quality is head and shoulders above the WH 48" deck... not to mention the maneuverability. If mowing speed/productivity is what you're after, get a ZTR. There is a reason why the professionals use Dixie Choppers, Scags, Exmarks, etc... they are the fastest way to cut a lawn with really good results. That said, I wouldn't recommend trying to plow, grade, till or pull a heavy trailer with those... :hand:

[Don1977 604]

It's more in the time it will take don't think the amout of gas used will be much different.

[IthacaJeff 151]

No offense taken, gents. It is straightforward advice. A ZTR would enable a faster and perhaps

better, cut. Been keeping my eye out for one the past two years that I could afford and at least

in reasonable condition. Been to auctions within a 45 mile radius. I got the Sunstar (actually

at Deutz Allis 1920) at a price within my budget and not even tow-behinds have come close.

I'm planning on mowing with the 60" Sunstar for the time savings for both me and my kids who mow.

I don't mind mowing, but the 2-3 hrs it now takes is time taken away from other, more important,

things. The fuel efficiency thing is more of a curiosity but does have some importance. In the two

years we have been in our new house with acreage to mow, versus the 1/2 yard we had before,

we have seen mowing fuel costs actually impacting our monthly budget. Of course, the skyrocketing

gas prices over that time have contributed.

Jeff

[MalMac 1,331]

This subject really can be answered only by the individuals needs. Everybody's is different. My situation is that I mow 3 relatively flat acres. I have 520's and some C series ranging in power from 8 to 14hp. The 520's really eat up the gas. Using a 520 with a 48" deck was doing the same work as a 14hp Kohler using the same deck. The difference being the amount of fuel used. Time factor was very little between the two. Now I did try to use a 10hp Kohler with a 42in deck which did a great job of mowing using even less gas, but the time factor got to the point I was just plain was getting tired of all the seat time. We had alot of rain here and was mowing every 5 to 7 days sometimes more frequent when the grass really took off and grew. What I finally did was put my 60in deck on the 520 knocked out the super large easy areas then used the smaller tractors to finish up. Using the big deck really knocked down the time factor by almost half. So all in all the gas usage became a mute point. The time factor really was the difference. Now with all that garbage being said I also have a Zero machine that no Wheel Horse tractor ever made can come close to the time frame it takes to do all the trimming and in and out of tight places. So like I said the answer to your question is everybody has different needs and there for size VS. time in mowing varys greatly from one person to the next.

[Hydro 131]

:twocents-02cents: I see no one has really commented about the 8 speed as opposed to the Hydro. You may not be happy with the cut of the the 416 in 3rd gear on some parts of your lawn. If that's the case then you would have to use 2nd gear in some areas. That would be definately slower than what you could do with the Hydro. You could equate that into time and money.

I think the Hydro is better overall for mowing especially if you have much stop and go or manouvering to do.

[wh500special 2,187]

For comparative purposes, you can consult a "productivity chart" from places like Exmark to see what kinds of differences you'll see by using various widths of cut at various speeds.

http://www.exmark.co...s/Productivity/

If fuel use is really important to you, you'd be wise to consider replacing all of your current equipment with a single diesel-powered machine. I have forgotten the specifics since I moved about 2 years ago, but mowing my 4-5 acres around my old house took vastly different amounts of time and fuel depending on what equipment I used. For example (going from foggy memory):

1. Ford Diesel Utility tractor (~23 hp) with a 72" 3pt mower = little less than 4 hours, 3.5 gallons diesel fuel

2. Toro/WH 724Z gasoline zero turn with 60" mower and 24hp Onan = 2.5 hours, 8 gallons gasoline

3. Kubota 28hp diesel zero turn with 72" deck = less than 2 hours, 2.5 gallons diesel fuel.

4. John Deere LT133 w/ 38" deck and 13 hp Kohler = never finished in one sitting...estimate 6 hours and probably 6 gallons gas.

I also mowed once with a C160H and 42" SD but don't remember how long it took. It seemed to take f-o-r-e-v-e-r though and drank a bunch of fuel. Plus, the tractor was miserable to operate since it was so loud.

None of the above counted trimming with the weedeater. With the Ford I still had a lot of trimming to do...like 2 hours worth. With the Toro and Kubota it went down to about 45 minutes and I only did it every other time...maybe even every third time.

All things being equal, your 20 hp engine ought to use about 25% more fuel per hour than your 16 hp. I'd ignore the fact that the hydro "uses" any power since no matter what hunk of iron you're driving around will take energy to motivate. The cut width of the 48" mower is 20% smaller than the 60-incher, so I'd guess your fuel consumption between the two competing machines will be about the same as long as you're varying your speed on the 20-horse to match the conditions (the advantage of a hydro).

To me, the reduction in mowing time would far outweigh the fuel cost. IMO.

As an aside, my understanding from one of the guys who worked for WH back when the Onans were introduced was that the Onan 20 put out more torque than the Kohler M20 and Briggs of the time. As did the 16's and 18's. This made handling the 60" deck on the 520 a bit easier. Plus, Onans are known for running long lives in most applications and are incredibly smooth.

It takes a specific amount of gasoline to produce 20hp. I'd suspect then that if you're running a 60" deck thru tall grass at a fast speed that ANY 20 hp engine will consume a lot of fuel. And they ought to be fairly close within brands. Theoretically, 20hp requires about a half a gallon per hour of gasoline if running at 100% efficiency. Assume about a 25% actual efficiency and you'll use - under full 20hp load - about 1.78 gallons per hour according to the back of my napkin. Nothing ever runs at 100% load for very long though.

You should easily see from my data above why the Kubota was my favorite grass mower. I bought it used for cheap, mowed with it for a couple of years, and sold it when I moved for more than I paid intially. The trick is being a cash buyer in the dead of winter when everything's covered with snow!

I guess the moral of my ramblings is that if you're going to have a big engine, you'd better have a big deck to make up for the fuel consumption.

Get more done, have more fun, get a diesel!

Steve

[sorekiwi 761]

I just love Steve's posts,

I'll start thinking about something, ponder on it for a week or two and finally ask the question, and BANG! he comes up with all the answers just like that! He even comes up the answers to the questions I havent thought of yet!

And most of us never have to "call Bullsh!t"!! :ychain:

[drscooby 0]

I used to be in the lawn care and had two apt complexes and I found out if you keep the blades sharp bearings greased about 4 mph around the buildings and 5th gear at 7mph in the open area. when you get done just roundup the rest you didn't cut and call it a flower bed and round off the corners, also alot less weedeating.

note if you drill a 1/16 hole, 180 degrees away from the grease fitting between the bearings, when you grease them up you will not blow the seals in you spindles

also thinking about getting rid of my Ex Mark 14 hp kaw, 48 inch, pull start, runs great need muffler.

[IthacaJeff 151]

With my 416-8 with the 48" deck I periodically mow in 3rd gear, which is really too fast

for a good cut, but on the wide open spaces it works. I tell the younger kids to mow in

2nd gear because taking corners gets a bit hairy and they don't take too much care

around the flower beds.

I too have tried to set up the trimming to be minimal . . . spaces between plantings are

sized to fit the mower, prudent use of roundup, and so forth. But, the 60" deck on my

DA 1920 may cause a few casualties amoung the plantings!

Jeff

[Herbl 10]

Jeff

I hear ya on the plants but that power steering is sure nice to get in and around the plants.....

Herb

[leeave96 487]

Here's my take on mowing with my Wheelhorse tractors - enjoy the ride. To me, if you need a zero turn to cut down on the time factor - definately do it. I just like a steering wheel in my hand vs two zero turn levers and there's something fun about riding around on a Wheelhorse vs. working at the salt mine.

Where I have mowed larger yards - like at my Church or my Dad's farm, we put more than one tractor on the grass. That get's me my Wheelhorse fix, exercises another tractor and cuts down on time.

I saw a new Sunstar about 10 years ago and that thing looked heavy duty. I think you will enjoy it too.

Good luck,

The other Bill

[IthacaJeff 151]

Yeah, the power steering is nice and the turning radius, even with the big 60" deck, seems about

half that of the 416.

[varosd 1,185]

I have to talk to people all day and really enjoy the "silence of the mower"! I only have an acre. this Spring, my newly refurbed Roxy gang reels will just about double my cutting width and that is always an option. different gang reel set ups to match you needs.

[IthacaJeff 151]

I almost placed a bid on a tow-behind gang mower, but came to my senses knowing myself. I'm

not the most diligent maintenance guy, and sharpening all those blades -- arghh! I used to work

for a small town highway dept. and we removed all the gang mowers, including the big Jake

tractor with all of its reels, to send out for sharpening.

Now, the new Toro out-front 60" mower with the steering wheel we had was a mowing beast.

Unstable as a teeter-totter, but fun!

Jeff

[buckrancher 2,679]

the best way to cut your mowing time and fuel in half Jeff is

make your yard half as big

Brian

[WH nut 553]

I really dont know why anyone would want to cut down on seat time. Its the most peacefull time I can find. Me, my horse and a beer, doesnt get any better.

[mrocket49 23]

I pull a 42" 8hp trail mower behind my C-175 for a total of about 80" of mowing swath using a combined 25 horsepower. I can mow my mostly obstacle-free 2 1/2 acres in a little under 3 hours.

The trail mower uses less than a gallon of gas and saves me 1-2 hours.

[WheelHorse_of_course 99]

This link offers some interesting points:

http://www.lsuagcenter.com/en/lawn_garden/home_gardening/equipment/lawn_garden_tractors/The+Effects+of+Width+and+Speed+on+Mower+Productivity.htm

Keep in mind flat head engines are less efficient than overhead valve machines.

cheers

Rolf

[Hydro 131]

I pull a 42" 8hp trail mower behind my C-175 for a total of about 80" of mowing swath using a combined 25 horsepower. I can mow my mostly obstacle-free 2 1/2 acres in a little under 3 hours.

The trail mower uses less than a gallon of gas and saves me 1-2 hours.

Weapon of Grass Destruction