Compact tractor horse power

[jenkinsph]

So in one sense you are wrong, people aren't buying horsepower that is useless to them, just because its not on a heavy tractor. In another sense you are right, it does take weight to put that power to the ground, so for ground engaging implements, it would indeed be useless horsepower at some point.

It all depends what the operator is using that power for, ground engaging, stationary, somewhere in between etc?

I agree with Piston and would add this.
Most of what I do is not at maximum drawbar loading, rather how fast can I pull an 8' landplane across the ground. Pulling a properly matched disk across the ground at speeds of 5 or 6 mph is another example, a heavy lower hp tractor with similar weight can pull the same disk but may not have the power to pull it fast enough to turn over the soil. Ground speed is an important consideration when making these comparisions.

If all you need the tractor for is to pull a subsoil point deep and slow then in this case a higher hp compact tractor won't be a benefit. Properly match your tractor and implements and you can better utilize your available hp.

 

[Midniteoyl]

I have a question on just lawnmower HP. I have an 80's model JD 332 diesel lawn tractor with advertised 14 hp and a 54" mower which it handles well. I also have a ZTS 6000 zero turn with 26 HP and 52" mower. Both mowers will mow at the same speed with no problems. How can 14 hp pull a larger mower deck as a 26 hp. My thoughts are it cant and that the lawnmower guys are using something different to calculate the motor HP from what was used in the 80's. I know that a 17hp Troybuilt mower I had wouldn't cut very well in deep grass due to lack of power and it only had a 48" deck. Sure the JD is diesel and likely has more torque but it runs much slower RPM than the gas engine also and it burns about half the quantity of fuel per hour for the same work load. Anyone know what changed.

Because, as in my previous post, the OEMs are using 'peak' hp nowadays as opposed to 'working' hp. The engine OEMs say stuff like '26hp' @ 3600rpm, but then limit the actual running RPMs to something like 2200-2700. Less RPMs, less HP. If the ZTR actually used all 26hp, it would be at such RPMs that it would blow.

 

[Piston]

I have a question on just lawnmower HP. I have an 80's model JD 332 diesel lawn tractor with advertised 14 hp and a 54" mower which it handles well. I also have a ZTS 6000 zero turn with 26 HP and 52" mower. Both mowers will mow at the same speed with no problems. How can 14 hp pull a larger mower deck as a 26 hp. My thoughts are it cant and that the lawnmower guys are using something different to calculate the motor HP from what was used in the 80's. I know that a 17hp Troybuilt mower I had wouldn't cut very well in deep grass due to lack of power and it only had a 48" deck. Sure the JD is diesel and likely has more torque but it runs much slower RPM than the gas engine also and it burns about half the quantity of fuel per hour for the same work load. Anyone know what changed.

Are they both diesel? Or is the 26hp gas? If it's gas, that explains it there.

 

[Gary Fowler]

The JD is diesel @14 hp but again, I can remember an old riding Lawn tractor my sister had that was also about 14 hp and pulled a 48" mower deck in the 1970's. 14 HP mowers today wont pull a 36" mower with out stalling down in 3" high grass and perhaps it is something to do with rating at higher RPM but I think they must have some other low down dirty rating philosophy to go along with that. My gas engine is 900 + cc (don't recall the exact number) but that is about the same size engine as the Yanmar that is in my J D diesel.

 

[bcp]

"One alleged deception involves stating the horsepower of the lawnmower as its gross horsepower, which is a theoretical maximum horsepower, not the more accurate net horsepower."
Lawnmower Class Action Settlement


B&S says they now use "gross torque."
https://www.briggsandstratton.com/us/en/support/faqs/engine-horsepower-or-torque-rating

Bruce

 

[Midniteoyl]

"One alleged deception involves stating the horsepower of the lawnmower as its gross horsepower, which is a theoretical maximum horsepower, not the more accurate net horsepower."
Lawnmower Class Action Settlement

Exactly.. It would blow shortly after hitting that HP number..


Kinda like those '1000 Watt' Home stereos in a box. If they were to ever hit 1000w (even combined), they would be smoking at the same time

 

[Midniteoyl]

The JD is diesel @14 hp but again, I can remember an old riding Lawn tractor my sister had that was also about 14 hp and pulled a 48" mower deck in the 1970's. 14 HP mowers today wont pull a 36" mower with out stalling down in 3" high grass and perhaps it is something to do with rating at higher RPM but I think they must have some other low down dirty rating philosophy to go along with that. My gas engine is 900 + cc (don't recall the exact number) but that is about the same size engine as the Yanmar that is in my J D diesel.

I picked up a Craftsman LT1000 (MTD) for free when the owner blew the 18hp twin Briggs in it mowing a hill. I put in a Briggs 11.5hp I/C single and now, according the po, it cuts better and outperforms the 18hp. Motors were simply better back in the day. Starting around 1990 or so, they really started to go to the dogs.

 

[Midniteoyl]

B&S says they now use "gross torque."
https://www.briggsandstratton.com/us/en/support/faqs/engine-horsepower-or-torque-rating

Bruce

Ya.. says nothing about the actual performance of the engine either.. 'torque ratings' BAH!

 

[Midniteoyl]

Briggs advertised one engine as having 6.75 horsepower and yet told the Environmental Protection Agency the same engine had 3.6 horsepower, an 88 percent overstatement, according to the lawsuit.

Mowers: Horsepower goes the way of the buggy - Houston Chronicle

 

[sd455dan]

I picked up a Craftsman LT1000 (MTD) for free when the owner blew the 18hp twin Briggs in it mowing a hill. I put in a Briggs 11.5hp I/C single and now, according the po, it cuts better and outperforms the 18hp. Motors were simply better back in the day. Starting around 1990 or so, they really started to go to the dogs.

That must have been a newer (18hp) twin that was sick... Still have 2 I/C Briggs twins (Industrial - Commercial) 1-16 hp and 1-18 hp both still run great the newer one is an 18 hp 1983.

The 16 hp was built in the 70s

also picked up a good running 11.5 i/c single at an auction for a friend and it has an identical mower deck and drive system as the 18 hp and there is no way the 11.5 cuts as fast or with as much power as the 16hp or 18hp twins...

These are as stated- all pre 1985 mowers and the fact that neither of the twins have had any work other than a couple sets of plugs, oil changes and air filter changes and one carb kit@ $11 can't say what work the 11.5 hp has had but it also runs well, just not as strong as the twins , or as smooth... IMO Still think both designs are solid...do have one mower design that has been Nothing but expensive trouble - a 4518 Honda hydrastatic, liquid cooled vertical twin, riding mower

others may have had different results