Easy question. My little Kubota B7510 has a roughly 20 HP diesel engine. My uncle's riding lawnmower, from Sears I think, has a 25 HP gasoline engine. My tractor engine looks a whole lot more serious than his lawnmower engine. Does his REALLY have more power, or are they rated differently?
HP vs HP
- Thread starter JCA
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DaveNay
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I believe thet the torque vs. rpm curve is more important than an "arbitrary"* horsepower rating.
*I say "arbitrary" because the hp rating that is printed on a sticker slapped on the side of the equipment is created by the marketing department.
Here is a pretty good explanation of how it all figures together.
Dave
*I say "arbitrary" because the hp rating that is printed on a sticker slapped on the side of the equipment is created by the marketing department.
Here is a pretty good explanation of how it all figures together.
Dave
Gatorboy
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</font><font color="blue" class="small">( Does his REALLY have more power )</font>
If you are talking Horse Power, then yes, he has more.
If you are talking Horse Power, then yes, he has more.
Bob_Skurka
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Much of the actual power of a tractor comes from the gearing of the machine.
I have a car that has about 300hp, I have a fleet of diesel trucks that have about 175hp. Which will haul more weight? The diesel trucks have the ability to pull loads in the 30,000 pound range, but my Avanti convertible would likely burn out the transmission trying to move that amount. This is very similar to the garden tractor versus CUT question.
There are also some serious torque issues involved, as previously mentioned. The garden tractor will have minimal torque compared to the CUT, which effectively means it will be unable to transmit the power to an implement or the wheels or both. For example: consider a high speed drill, they typically have very low torque and it is pretty easy to get the bit stuck in a fairly thin piece of metal when drilling, but a drill with greater torque and lower power can easily drill through the same material without binding.
There are also some additional issues as well, such as transfer efficiencies. A hydrostatic transmission is slighly less efficient than a gear transmission and consequently a tractor with a HST tranny will put 1 or 2 hp LESS to the PTO than will a tractor with a GEAR transmission. That said, your uncle likely has a glorified fan belt that drives off a spindle at high speed and is reduced down to run the rear wheels and the mower deck. SHORT OF MENTAL TELEPATHY, it is probably the least efficient way to transfer power I can think of.
So, a garden tractor may need more power simply to do less work because of a combination of the above factors because many things conspire against its abilities. And most of the reasons are cost related. It is often cheaper to up the HP of the tractor than to put in a more efficient transmission, gearing, etc.
Further, much of the reason I think (MY OPINION ONLY) for garden tractors having such large HP engines falls into the TIM TAYLOR line of thinking. If 12 hp is good, then 24 is TWICE as good! ARG! It is simple marketing. Give the caveman more power and stroke his ego.
I have a car that has about 300hp, I have a fleet of diesel trucks that have about 175hp. Which will haul more weight? The diesel trucks have the ability to pull loads in the 30,000 pound range, but my Avanti convertible would likely burn out the transmission trying to move that amount. This is very similar to the garden tractor versus CUT question.
There are also some serious torque issues involved, as previously mentioned. The garden tractor will have minimal torque compared to the CUT, which effectively means it will be unable to transmit the power to an implement or the wheels or both. For example: consider a high speed drill, they typically have very low torque and it is pretty easy to get the bit stuck in a fairly thin piece of metal when drilling, but a drill with greater torque and lower power can easily drill through the same material without binding.
There are also some additional issues as well, such as transfer efficiencies. A hydrostatic transmission is slighly less efficient than a gear transmission and consequently a tractor with a HST tranny will put 1 or 2 hp LESS to the PTO than will a tractor with a GEAR transmission. That said, your uncle likely has a glorified fan belt that drives off a spindle at high speed and is reduced down to run the rear wheels and the mower deck. SHORT OF MENTAL TELEPATHY, it is probably the least efficient way to transfer power I can think of.
So, a garden tractor may need more power simply to do less work because of a combination of the above factors because many things conspire against its abilities. And most of the reasons are cost related. It is often cheaper to up the HP of the tractor than to put in a more efficient transmission, gearing, etc.
Further, much of the reason I think (MY OPINION ONLY) for garden tractors having such large HP engines falls into the TIM TAYLOR line of thinking. If 12 hp is good, then 24 is TWICE as good! ARG! It is simple marketing. Give the caveman more power and stroke his ego.
crown
Platinum Member
As others have metioned the HP on the machine is marketing, hook your tractor to his tractor and have a pulling match you will easily drag him around your yard without any effort. /forums/images/graemlins/laugh.gif
Bob_Skurka
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crown, great idea, but drag him around on HIS yard because his wheels will be spinning while you drag him around and there is a good possibility that the spinning will tear up his lawn.
crown
Platinum Member
You make a good point!!! /forums/images/graemlins/smile.gif
lablovers
Silver Member
Bob,
You have an Avanti? Pictures man I need to see pictures. /forums/images/graemlins/grin.gif
You have an Avanti? Pictures man I need to see pictures. /forums/images/graemlins/grin.gif
Bob_Skurka
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</font><font color="blueclass=small">( Bob,
You have an Avanti? Pictures man I need to see pictures. /forums/images/graemlins/grin.gif )</font>
Yes, I have an Avanti convertible. I believe it is convertible #28 off the assembly line of total of 78 cars built that year. It is silver with black top, charcoal leather interior, walnut burl dash and doors. The original BF Goodrich tires dryrotted from lack of use about 3 years ago. I have a bit over 20,000 miles on it. For those who know about Avanti cars, mine is classified as a "Kelly" car and is one of the few years produced in Ohio.
I bought it from the original owner who bought it at a dealership in New Jersey. Unfortunately, the original owner is now dead. He was an executive who worked at Windows of the World restaurant in the Twin Towers in NYC and is one of the 3000 who died when the towers were hit by the airplanes during the terrorist attack.
As for pictures, I don't think I have any digital pictures. But I suppose it would be a good excuse to get the car out of storage to take some shots.
You have an Avanti? Pictures man I need to see pictures. /forums/images/graemlins/grin.gif )</font>
Yes, I have an Avanti convertible. I believe it is convertible #28 off the assembly line of total of 78 cars built that year. It is silver with black top, charcoal leather interior, walnut burl dash and doors. The original BF Goodrich tires dryrotted from lack of use about 3 years ago. I have a bit over 20,000 miles on it. For those who know about Avanti cars, mine is classified as a "Kelly" car and is one of the few years produced in Ohio.
I bought it from the original owner who bought it at a dealership in New Jersey. Unfortunately, the original owner is now dead. He was an executive who worked at Windows of the World restaurant in the Twin Towers in NYC and is one of the 3000 who died when the towers were hit by the airplanes during the terrorist attack.
As for pictures, I don't think I have any digital pictures. But I suppose it would be a good excuse to get the car out of storage to take some shots.
L
LarryRB
Guest
th3e Avantis built in Ohio, weren't they built on modified Pontiac Firebird frames?
