I can't speak for your 12HP CC, but I have mowed with both a 10HP and 14HP machine for many years. While I agree that they never bogged down, the discharge chutes did clog quite often in thick wet grass. With 20HP its not an issue.

I would almost dare to bet the HP ratings are calculated differently nowdays. I don't think my 1999 GT235 18 horse Briggs has the same torque and power that my dad's 1984 318 18 horse Onan has. I agree that everybody is pushing more horsepower to sell their products, but I wonder how honest those figures stack up against those of the past.

The increasing popularity of mulching as opposed to bagging or just discharging takes a lot more horsepower,esp when the grass is a bit too long or damp

Still I think why do you need 26 HP on a 42 inch deck? What could possibly need that much power?

Does size make a difference??

HP is rated at 3600 RPM minus "accessories" such as cooling, charging, muffler etc.
In actual use, they are governed to about 3000 RPM or so. That results in a major reduction of actual HP.

From the Kohler website for example-

"Horsepower ratings (shown as gross) are in accordance with Society of Automotive Engineers Small Engine Test Code J1940. Actual engine horsepower is lower and affected by, but not limited to, accessories (air cleaner, exhaust, charging, cooling, fuel pump, etc.), application, engine speed and ambient operating conditions (temperature, humidity and altitude). For more information, contact Kohler Co. Engine Engineering Department. Kohler Co. reserves the right to change product specifications, designs and standard equipment without notice and without incurring obligation."

Now for the smaller engine "Torque Rating" that you are starting to see-

"Gross power rating for individual gas engine models is labeled in accordance with SAE (Society of Automotive Engineers) code J1940 (Small Engine Power & Torque Rating Procedure), and rating performance has been obtained and corrected in accordance with SAE J1995 (Revision 2002-05). Torque values are derived at 3060 RPM; horsepower values are derived at 3600 RPM. Actual gross engine power will be lower and is affected by, among other things, ambient operating conditions and engine-to-engine variability. Given both the wide array of products on which engines are placed and the variety of environmental issues applicable to operating the equipment, the gas engine will not develop the rated gross power when used in a given piece of power equipment (actual on-site or net horsepower). This difference is due to a variety of factors including, but not limited to, accessories (air cleaner, exhaust, charging, cooling, carburetor, fuel pump, etc.), application limitations, ambient operating conditions (temperature, humidity, altitude), and engine-to-engine variability. Due to manufacturing and capacity limitations, Briggs & Stratton may substitute an engine of higher rated power for this Series engine)"

The higher horsepower engines will invariably have higher torque, which is a more relevant parameter for tractors/mowers than horsepower. Especially at lower RPM. Higher torque will really show when you hit thick or wet grass, or encounter a higher load on the engine in tractor use. The lower HP machine will not react as easily or quickly.

But, if you were happy using the lower HP units in your environment, then by all means, stay in that range. If you demo a higher HP unit though, you may find out what you were missing.

Having a higher HP rated machine does not automatically mean you are going to use more fuel though. With some minor variations, fuel useage will be basically the same to do a particular job (same machine) no matter the HP rating of the engine. The Higher HP engine will do it at a much lower throttle plate opening, thus using almost the same fuel, but have power to spare when needed.

I have to beleive standards for rating horsepower have changed over the years, My old 12 HP Cub had as much reserve power as my 18 HP Toro does now. On the other hand fuel consumption is about the same, and the Kohler V-twin is quieter and smoother than the old one-lung. I still miss that tractor, it took everything I dished out and came back for more.

The best way to figure it out would be to take an old 12HP and put it on a new tractor (of course, who would do this) that comes stock with 25 or so HP to see if it runs/mows/pulls the same. I have a 15HP Kaw. Twin on my tractor and it has had no problems with anything I have thrown at it so far.

So what exactly do you do with all that reserve power other than waste fuel?

Mow my cabin's lawn that grows 3 foot tall lawn (the lowest foot is always wet) that grows uncut between memorial day and the 4th of July. Mow the balsam/poplar/hawthorn saplings that are always springing up in my trails. Snow blow clear the 2 or 3 feet of late fall early winter snow when making the last trip of the year.

I have an utility tractor but the little GT is often quicker in small areas and takes less effort to maintain. I think high HP engines on LT/GT are like 4 wheel drive. Most people never really need it; and of the few who do its needed only a fraction of the time. But it is extremely nice to have when the situation calls for it.

"The higher horsepower engines will invariably have higher torque..."
Typically, but not always.

http://www.tewinc.com/pdf/350700.pdf
http://www.tewinc.com/pdf/351700.pdf

I've got several Wheel Horses from 7 to 20 HP that can all use the very same mower deck and most have a similar 6-speed transaxle. Swapping my 48" mower deck around the different tractors allows for a pretty much apples to apples comparison of engine performance. This deck is a std. side discharge and I alternate between OEM and Gator blades. My lawn is just over an acre minus the home's footprint and has a combination of flat and hills.

The 7HP tractor will run the 48" and I have used it to mow several times, but it is slower as hills and heavier grass quickly pull the engine down. Next up is an 11HP, and this is the tractor we most often use with this mower. It works fine for the routine mowings and the engine handles the load fine except in the heaviest, most dense grass that can be typical of springtime when we've had plenty of rain and we get a few days behind on mowing. The 11HP also seems to be the most fuel efficient for routine mowing of the lawn. Next in power is a 12HP hydrostatic drive tractor. This one really doesn't perform quite as well as the 11HP gear drive, presumably due to the extra power absorbed by the hydro. I'd guess the hydro consumes as much as 2-3HP compared to a gear drive. My next tractor jumps to a 20HP Onan twin, and originally came to me with a 60" deck. It runs the 48" just grand and is a bit faster when mowing the lawn, I believe simply because the engine never significantly drops rpm for the hills or heavy spots. When the governor kicks in on the Onan, it has a real sound and feel of authority!

I also maintain a family cemetery and surrounding field of about 1/2 acre in the country, but I only get there every 4-6 weeks. The 20HP is my favorite to take, because I know I'll get the job done without fuss. However, the 11HP sometimes gets used and does a fine, albeit slower job in the tough stuff.

I'm still itching to try a couple 14 to 16HP tractors for comparison and it would be interesting to compare a 16HP single Kohler with a 16HP twin. Overall, I'd have to say my favorite for mowing is the 20HP, not just for the power but also for the more pleasant twin cylinder sound and the taller, more comfortable seat on that tractor. But the wife prefers the 11HP tractor so that's the one the mower deck usually stays on! Ed.

Thats great your wife lets you keep four tractors!

You don't need 26 HP with a 42 inch deck . . . . and it probably doesn't actually have anywhere near 26 HP - Inflated ratings

My 19 HP 3 cylinder diesel Kubota has a 54 inch deck and the same tractor is available with a 60 inch deck. My experience with the 54 indicates that the engine would probably have no problem with the 60 inch deck, as I have no problem wading through 18 inch tall grass and weeds, mowing it down to 2 1/2 inches in a single pass with little clogging . . . . and NO bogging down

I'll take 20 watercooled diesel horsepower over 30 air cooled gasoline horsepower any day ;-)

Don

Where we hunt Deer there's a six foot wide path that's probably 1/4 mile long. This path grows all year after Deer season untill the fellows start using it for getting to the woods in Archery season. Me and my one son have been cutting it every year for a long time and I'm now using my 3rd tractor on it . Along time ago I had a 12 HP that had a rough time getting through it with the deck raised, Sometimes it stalled out. About 8 years later I had a 18 HP that did a little better but it worked pretty hard for me to get it cut down. Now I have a GT5000 with a 25 HP that goes through it like butter. I do agree that you don't need that much horse power for mowing grass but with this tractor I can pull a big steel wagon loaded with billits of wood and cut this path without putting a strain on my tractor. For me I like the extra horse power but if I was only mowing grass I wouldn't need more than a 10 or 12 HP. I think Tim the Tool man taylor started it all when he kept saying (MORE POWER ) ! Pap

I have an old case 220 which is a 10 horse kohler single, hydraulic transmission, and it will mow heavy,wet grass with a 40 inch deck with no problem. I've considered getting a larger-engined case but have not yet found the need. It also uses very little gas,starts at minus ten and never uses oil. Its a 1970 model. They do make them like they used to but they cost an arm and both legs!!

I have a JD325 with an 18hp Kawasaki Air Cooled Engine. It sure has enough HP for anything I use it for, which is mainly mowing with a 48" deck or pulling a JD 10P cart full of dirt up hill. If I let the grass get really long, I slow down my ground speed to give the deck more time to shred the grass into smaller pieces, not because the engine bogs down. I think I have a good match of engine, transmission, and deck for my application. Certainly there are others who really need more power. If that is the case, I hope they select a tractor that has a stronger frame and transmission to match the engine capabilities. Charles Ranheim

I don't think you can compare Little yard mowers to actual farm tractors. The HP rating are different on early drawbar measurements as is farm tractor or Trains, you lawn tractor rating is calulated rather than a pulling power measured figure.

I have a hard time beleiving that some of these 25+ HP tractors have the frame, tranny and other guts to handle that muh power and transfer it to the ground efficiently. I just dont think aluminum trannys can handle that kind of power.

Having a higher HP rated machine does not automatically mean you are going to use more fuel though. With some minor variations, fuel useage will be basically the same to do a particular job (same machine) no matter the HP rating of the engine. The Higher HP engine will do it at a much lower throttle plate opening, thus using almost the same fuel, but have power to spare when needed.

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This is true ,however when mowing grass max RPM's are needed so the higher torque ,lower RPM advantage of a larger engine is lost.
My 25hp twin uses almost exactly 2x the amount of fuel that my 12.5hp single does when mowing grass.

Its possible the higher HP increases are for better fuel consumption , think of it as its not working as hard to mow the yard or do chores- its like putting a large motor in a lil car- you'd be able to fly in it and the motor will be barely cranking over.
I currently own 17 different brands of lawntractors with different motor displacements ( all Briggs and Stratton motors) from 5HP to 18.5HP - when i used to mow 2 acres of grass, it really didnt seem much of a difference in fuel consumption, depending on how tall/thick the grass was and how fast i was going then obviously i used more. Typically i could nearly mow the whole thing on one full tank of fuel, but refueled it close to being empty, just in case. Im sure todays motors are more efficient, more enviromentally friendly then previous years.
Kidd

All things being equal - And if I recall correctly, increase the HP 30% over required and extend the engine design life by 70%.

Would think in the marketing game - Higher HP allows one to use a lesser quality engine for a given application and still maintain a fair degree of usable durability.

Could it be because we have become fatter in general? The hospital I worked at 2 years ago had to replace its CT scan tables because the weight limit was 400 pounds.

I think I've got 25hp on my lawnmower. Runs a 62" deck nice. I mow a few acres of christmas trees and don't always keep up like I should. When running the 5' back blade or cultivator I never use more then half throttle. I have several 3'-4' foot boulders around my lawn... nice to put the back blade on them and scoot them over so I can mow under them. Fuel injection really makes it act different. Kept my old lawnmower with 18hp and a 54" deck because it fits between the mature trees better. It grunts a little running a 42" snowthrower but seldom has any trouble with cutting grass. Both machines have a liquid cooled Kawasaki engine but so far I much prefer the new fuel injected one.