Eating a Bit of Crow Regarding Horsepower

MOturkey

LawnSite Silver Member
Location
Bolivar, MO
Three weeks or so ago, I responded to a thread, can't recall the title, where the discussion involved the horsepower of mower engines and cutting efficiency, etc. I expounded, at great length I might add, about the additional cost of fueling the higher horsepower engines, and thought little or nothing was to be gained, under normal mowing conditions, by running more horses. I stated I had never felt my previous, Z's to be underpowered, even though the engines were rated well below many of those being used today.

I have two Gravely 460's. One has the Kohler EFI, which according to the specs on their current product line, is 26.5 hp (I always thought it was 29?). My newest mower has the XF2 deck, and a 31 hp Kawasaki. I've run both extensively, and like the increased fuel efficiency of the Kohler (approximately 1.1 GPH vs. 1.75 GPH), and never really noticed the power difference, as I generally don't "push" the mower to the limits.

A couple of weeks ago, my wife, who helps me mow almost every day, ended up in ICU with a terrible cough and labored breathing and a then unknown diagnosis. Her two daughters were there the second day, so I went home, got a few hours sleep and went to mow as much as I could so as to try and stay caught up with the mowing.

I was working as fast as possible so I could get done and return to the hospital, and when I had my last two accounts left, both large properties with very thick grass, I switched to the newer mower with the 31, primarily because of the FX2 deck, which does a better job of dispersing clippings when in thick and/or wet conditions.

Worried, of course, and wanting to get done as quickly as possible, I started pushing the mower as fast as possible on the terrain, and was surprised to find out that it was almost impossible to bog down the 31. Even though this was a weekly account, I was cutting up to 6 inches of grass off in places, and the 31 would do this no matter how hard I pushed. When I finished the first lawn, I looked at my watch, and realized it had taken 15 to 20 minutes less than the fastest I could ever recall mowing it, even during periods of slower growth.

I've since done a bit of comparing the two mowers, and find I can cut mowing time considerably in difficult mowing conditions with the 31. So, I'll wipe the egg off my face and apologize to those who advocate the larger horsepower engines. Some of this could be attributed to the newer deck design of the FX2, but when pushing the mowers, I can definitely tell the Kohler begins to struggle well before the Kawasaki.

My conclusion is that if you mow primarily smaller properties, and/or properties that don't have heavy growth, sticking to the smaller horsepower, more fuel efficient engines will be more cost effective.

However, if you mow larger properties with thick growth, especially a lot of bi-weekly accounts, the higher horsepower engines may well be warranted. This would be especially true if you are not solo and trimming mowing time reduced labor costs, or were solo and need more hours in the day.

My wife, by the way, is now doing fine after lots of antibiotics to fight what was eventually diagnosed as bacterial pneumonia. I am keeping her off the mower for a while, though. :)
 

32vld

LawnSite Gold Member
Location
Long Island, NY
Three weeks or so ago, I responded to a thread, can't recall the title, where the discussion involved the horsepower of mower engines and cutting efficiency, etc. I expounded, at great length I might add, about the additional cost of fueling the higher horsepower engines, and thought little or nothing was to be gained, under normal mowing conditions, by running more horses. I stated I had never felt my previous, Z's to be underpowered, even though the engines were rated well below many of those being used today.

I have two Gravely 460's. One has the Kohler EFI, which according to the specs on their current product line, is 26.5 hp (I always thought it was 29?). My newest mower has the XF2 deck, and a 31 hp Kawasaki. I've run both extensively, and like the increased fuel efficiency of the Kohler (approximately 1.1 GPH vs. 1.75 GPH), and never really noticed the power difference, as I generally don't "push" the mower to the limits.

A couple of weeks ago, my wife, who helps me mow almost every day, ended up in ICU with a terrible cough and labored breathing and a then unknown diagnosis. Her two daughters were there the second day, so I went home, got a few hours sleep and went to mow as much as I could so as to try and stay caught up with the mowing.

I was working as fast as possible so I could get done and return to the hospital, and when I had my last two accounts left, both large properties with very thick grass, I switched to the newer mower with the 31, primarily because of the FX2 deck, which does a better job of dispersing clippings when in thick and/or wet conditions.

Worried, of course, and wanting to get done as quickly as possible, I started pushing the mower as fast as possible on the terrain, and was surprised to find out that it was almost impossible to bog down the 31. Even though this was a weekly account, I was cutting up to 6 inches of grass off in places, and the 31 would do this no matter how hard I pushed. When I finished the first lawn, I looked at my watch, and realized it had taken 15 to 20 minutes less than the fastest I could ever recall mowing it, even during periods of slower growth.

I've since done a bit of comparing the two mowers, and find I can cut mowing time considerably in difficult mowing conditions with the 31. So, I'll wipe the egg off my face and apologize to those who advocate the larger horsepower engines. Some of this could be attributed to the newer deck design of the FX2, but when pushing the mowers, I can definitely tell the Kohler begins to struggle well before the Kawasaki.

My conclusion is that if you mow primarily smaller properties, and/or properties that don't have heavy growth, sticking to the smaller horsepower, more fuel efficient engines will be more cost effective.

However, if you mow larger properties with thick growth, especially a lot of bi-weekly accounts, the higher horsepower engines may well be warranted. This would be especially true if you are not solo and trimming mowing time reduced labor costs, or were solo and need more hours in the day.

My wife, by the way, is now doing fine after lots of antibiotics to fight what was eventually diagnosed as bacterial pneumonia. I am keeping her off the mower for a while, though. :)

Problem is you are not just comparing different HP, different engines have different torque curves, carb vs FI, different brand mowers, different models/types within one brand, then even the same brand mower and model still can have different deck options.

My unscientific research has shown that newer mowers use less GPH then mowers made ten years ago.
 

Ridin' Green

LawnSite Fanatic
Location
Michigan
Yes, glad your wife is doing much better and hope she gets over it completely.

I am of the belief that it's better to have it and not need it, than need it and not have it. A bigger engine not only can pull you through tough times easier, it works far less hard at cutting under normal conditions.

BTW- the "26.5" EFI is actually 25.5 when rated under the J1995 system that Kawi uses (and Kohler is supposed to be using). Take a look at the spec page for the 26.5, way down at the bottom of the specs.
 

sjessen

LawnSite Fanatic
Location
Knoxville, Tn
Yes, glad your wife is doing much better and hope she gets over it completely.

I am of the belief that it's better to have it and not need it, than need it and not have it. A bigger engine not only can pull you through tough times easier, it works far less hard at cutting under normal conditions.

.

Could not agree more with this post. There is a local lco who has a mower with really high hours. He bought it with the bigger engine and though it is getting tired it still does the job whereas if her had gotten the smaller one he would have likely had to replace it by now.
 

dathorpe

LawnSite Senior Member
Location
Marshall, Va.
Yes, glad your wife is doing much better and hope she gets over it completely.

I am of the belief that it's better to have it and not need it, than need it and not have it. A bigger engine not only can pull you through tough times easier, it works far less hard at cutting under normal conditions.

In 2013, I purchased three 61" Turf Tigers. 2 Kohler 29hp, 1 Vanguard 35hp. This past spring, I traded in one 29hp with roughly 400 hours on the clock towards a 2014 35hp Vanguard. I'll probably keep the remaining 29hp... at least until they throw a 34hp or larger EFI on a Turf Tiger.

Point blank - I've come to believe that though you may save money on fuel with a smaller engine, the larger engine is much more productive.

BTW- the "26.5" EFI is actually 25.5 when rated under the J1995 system that Kawi uses (and Kohler is supposed to be using). Take a look at the spec page for the 26.5, way down at the bottom of the specs.

Ohhhhhhhh Ridin' (shakin' my head), you've got to get past this Kohler thing, buddy. There's more to life.
 

LibertyFarmLandscaping

LawnSite Bronze Member
Location
NE TX
In 2013, I purchased three 61" Turf Tigers. 2 Kohler 29hp, 1 Vanguard 35hp. This past spring, I traded in one 29hp with roughly 400 hours on the clock towards a 2014 35hp Vanguard. I'll probably keep the remaining 29hp... at least until they throw a 34hp or larger EFI on a Turf Tiger.

Point blank - I've come to believe that though you may save money on fuel with a smaller engine, the larger engine is much more productive.



Ohhhhhhhh Ridin' (shakin' my head), you've got to get past this Kohler thing, buddy. There's more to life.

Funny how opinions vary. I have probably 25% eow lawns and haven't missed the 35 VG TT I traded for my Kohler efi Gravely 460. I run high hours though. 6-800 per yr so it's a significant fuel savings. I feel like the quicker compensation of the efi makes up for some of the lower hp. Also make better time on a lot of big rough properties with the air ride seat.
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Ridin' Green

LawnSite Fanatic
Location
Michigan
In 2013, I purchased three 61" Turf Tigers. 2 Kohler 29hp, 1 Vanguard 35hp. This past spring, I traded in one 29hp with roughly 400 hours on the clock towards a 2014 35hp Vanguard. I'll probably keep the remaining 29hp... at least until they throw a 34hp or larger EFI on a Turf Tiger.

Point blank - I've come to believe that though you may save money on fuel with a smaller engine, the larger engine is much more productive.



Ohhhhhhhh Ridin' (shakin' my head), you've got to get past this Kohler thing, buddy. There's more to life.

Not for me, at least when it comes to dishonest advertising practices. The entire reason for that huge lawsuit was the same practice, only on a larger scale. The only way these companies will quit that crap is when enough people become educated on the fact that they are still doing it.
 

echo

LawnSite Bronze Member
Yes, glad your wife is doing much better and hope she gets over it completely.

I am of the belief that it's better to have it and not need it, than need it and not have it. A bigger engine not only can pull you through tough times easier, it works far less hard at cutting under normal conditions.

BTW- the "26.5" EFI is actually 25.5 when rated under the J1995 system that Kawi uses (and Kohler is supposed to be using). Take a look at the spec page for the 26.5, way down at the bottom of the specs.
Glad to see you've come around. It certainly is better to pay up and have the power.
Posted via Mobile Device
 

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