Rated HP vs Net

[Hilbilly]

I've been doing some comparison shopping, looking at Massey 1758 / 1759 and the Kubota L6060 / M7060. Mostly I've been comparing the "rated" hp of each. The Kubota owners manuals don't list rated hp but do list the net estimated engine hp and factory observed PTO hp. The Massey owners manuals repeat the same information given in the brochure but exchange the hp descriptions from rated to estimated.

L6060 Brochure
engine rated = 62hp ....... engine net = 60hp
pto = 53hp (doesn't state rated or net)

L6060 Owners Manual
engine net = 60hp manufactures estimate
pto = 53hp factory observed

M7060 Brochure
engine rated = 74.3hp......engine net = 71hp
pto = 64hp (doesn't state rated or net)

M7060 Owners Manual
engine net = 71hp manufactures estimate
pto = 64 factory observed

Massey 1758 & 1759 Brochure
engine rated = 59hp
pto rated = 44.4hp for 1758 and 45.6hp for the 1759

Massey 1758 & 1759 Owners Manual
engine estimated gross = 59hp
pto estimate = 44.5 cab and 45.6 platform

So what I have discovered is that I am not comparing apples to apples.

The things that stand out for me is;
1) Massey presents their information with the biggest numbers, ie rated or gross. They provide no net information.
2) Kubota lists the net estimated engine hp in the brochure and factory observed PTO hp. Curious as to what the estimated gross or net PTO hp would be.

I don't intend this to be a bashing thread of either Brand. Obviously I am considering both because I like them both.

EDIT: revised numbers to reflect the error of kw vs hp as noted in the 2nd post. Thanks for that.

 

[Seven Gables]

On your kubota owners manual specs I think those are kW numbers, pretty sure their cant be that big of difference in hp between the two, brochure and owners manual. B

 

[Hilbilly]

You are right!!!! In the Brochure the hp is listed first and the KW follow in brackets. In the manual it is reversed. I need to fix the numbers or delete the thread.

 

[Hozzie]

Typically net HP is simply a calculation of how much of the engine HP makes it to the ground vs what HP the engine produces. PTO HP Estimated is based on a percentage calculation similar to net HP that takes into account mechanical loss. For whatever reason, Kubota's system seems to have less % loss in PTO that a lot of other brands. I don't believe they are making it up, I have seen tests that confirm the HP numbers for the PTO.

The 7060 numbers of 71 and 64 are the correct values. I can't say if the MF numbers are net or estimated, but it is a big difference either way. The MF's would be closer in spec the the MX5800 from Kubota. It is 61 Gross/58 Net/50 PTO. I have one and really like it.

A Kubota will typically weight less in a similar size which is important (more weight is better). I have filled tires, etc to make some of that up. Unless you have a size issue for getting into and out of places and cost is not your main concern, I think the M7060 is certainly more tractor that the MF's.

 

[aczlan]

Gross engine horsepower is how much is put out by the force of the cylinders pushing on the crankshaft through the connecting rods.

Net engine horsepower is how much is left over after running accessories such as the water pump, alternator, etc.

PTO horsepower it is how much horsepower makes it through the transmission and out to the PTO.

PTO horsepower will be less on hydrostatic tractor then on the same model gear driven tractor as the hydrostatic transmission is always pumping some fluid in the low pressure circuit to keep the high pressure pump for the hydrostatic transmission from starving.

Calculated PTO horsepower is likely using an estimate of how much horsepower the transmission loses for parasitic losses.

Observed PTO horsepower is likely from putting the tractor on a PTO dynamometer and seeing how much horsepower it puts out through the PTO.

Aaron Z

 

[TheMadOne]

I feel Kubota is more transparent than most when it comes to net vs gross vs observed hp.

Kuboata put a dyno on a L6060 and it produced 53 PTO HP. PTO HP is what matters. I don't care if I have a 37HP or 35HP tractor. I have 28 PTO HP. Massey using calculated PTO HP isn't really bad, per say. Most companies are so paranoid about overselling the PTO HP on their units that actual testing will reveal an extra HP or two. I wouldn't be surprised to see the 1758 hit 45.5 PTO HP in actual testing.

A lot of dealers have PTO dynos. Anybody with a 1758 want to do a pull for science?

 

[finn1]

Dealership pto dynamometer are notoriously inaccurate. SAE power ratings are run / corrected to standard temperature and barometric pressure. Dealership dynamometer systems typically don’t have the sofisticated controls or software todo this, so power recorded is simply a snapshot at whatever conditions exist at that particular dealership, at that specific atmospheric condition, on that specific day.

A fully equipped and calibrated laboratory dynamometer system, with proper controls, costs several million dollars.

Also, consider that engine to engine and tractor to tractor variability for a given model will be several percent of the advertised numbers.

The tractors sent to the Nebraska tractor tests were always factory / laboratory tuned to the top of the spec.

Bottom line: don’t get too wound up over a couple of horsepower fifference between tractors from different manufacturers when making a decision. Spend some time making sure the features and ergonomics are suitable for you.

 

[Sawyer Rob]

For ME, it's the pto that does the work, so I don't care what the other hp ratings are!

I always compare pto hp...

SR

 

[Hilbilly]

Dealership pto dynamometer are notoriously inaccurate. SAE power ratings are run / corrected to standard temperature and barometric pressure. Dealership dynamometer systems typically don’t have the sofisticated controls or software todo this, so power recorded is simply a snapshot at whatever conditions exist at that particular dealership, at that specific atmospheric condition, on that specific day.

A fully equipped and calibrated laboratory dynamometer system, with proper controls, costs several million dollars.

Also, consider that engine to engine and tractor to tractor variability for a given model will be several percent of the advertised numbers.

The tractors sent to the Nebraska tractor tests were always factory / laboratory tuned to the top of the spec.

Bottom line: don’t get too wound up over a couple of horsepower fifference between tractors from different manufacturers when making a decision. Spend some time making sure the features and ergonomics are suitable for you.

I love the tractor I have other than some issues that need to be worked out but I would like to try either the Massey 1758 of the Kubota L6060 just to get a feel for the difference in power from the one I have. The problem is that none of the Massey dealers anywhere within 200 miles has a 1758 for me to try and I'm told the only way to get one is to have a stock one shipped up from a US dealer or to order one from the factory. You bet they're not doing that without a knowing there will be a sale. The Kubota dealers have just got their new shipments in but the tractors have not yet been assembled. I guess I could sit in the cab but it would feel weird being in a tractor with no wheels. The Kubota dealer I talked to today said these things move fast this time of year, so I'm thinking I won't get to test drive one and there is no way I would spend $65,000 for a tractor without getting a long test drive. There aren't any of these tractors in BC for me to try right now, used or new. Doesn't bode well for being able to negotiate on the prices.

 

[Hilbilly]

For ME, it's the pto that does the work, so I don't care what the other hp ratings are!

I always compare pto hp...

SR

I guess it really depends on the individual owners needs. I rarely use the PTO and when I do, it's usually for something that doesn't need a lot of HP. The only thing I need PTO hp for is the snow blower and I didn't even need to use it this winter. For me the biggest need for power is when pulling the boxblade or pushing the snow plow uphill. Even just traveling up my driveway it would be nice to have a little more HP so I could travel a bit faster.