How do they make several different HP tractors with all the other specs being the same?

[DieselBound]

In my original question I meant that, if you look at the sales literature or data sheet, there are many numbers to describe engine, frame, hydraulics, PTO, transmission, and on and on, arranged in a neat table. And if you look across models, every single number is exactly the same, except for the horsepower. They report weight to the pound, for example. If the higher horsepower tractor had an added turbocharger, there would have been more pounds. Unless of course the numbers are wrong, in which case there's no way to compare specs.

The idea that a higher horsepower model would consume more fuel is something I didn't think about, and it's an excellent point! Except that if the 40, 50, and 60 horsepower models all consumed the same fuel when actually delivering 25 horsepower, then it doesn't matter. I don't know if this is the case.

Turbos, and associated equipment, are really small on CUTs (and I thought the turbo on my 1.9L TDI was small; the one on my NX is like a little toy!) and wouldn't likely tip any scale to any significant degree, so weight isn't likely going to show any difference.

I wouldn't assume that fuel efficiency across the suite of engines is necessarily the same. In order to achieve higher HP ratings it's quite possible that a given power range's efficiency could be lower than a lower HP tuned engine. You'd have to look at the fuel mapping tables to see what's going on. That said, I doubt that there's going to be any significant difference in fuel efficiency (there most likely is SOME difference, but it's likely small), in which case going with a higher HP rating will come down to whether one can pony up the additional money for purchase.

 

[SmallChange]

If you want to know how 40, 50, or 60 hp engines compare when delivering 25 hp, then I think you will do better looking at the graphs of torque vs RPM.

I meant, how do their fuel consumptions compare? I don't think I've found that in the documents I've seen.

Burning more fuel at the same (moderate) power would definitely be a disadvantage for higher HP engines in the same application, as several suggested. I just don't know if it actually happens. Does anybody have data?

 

[pmsmechanic]

I meant, how do their fuel consumptions compare? I don't think I've found that in the documents I've seen.

Burning more fuel at the same (moderate) power would definitely be a disadvantage for higher HP engines in the same application, as several suggested. I just don't know if it actually happens. Does anybody have data?

Nebraska tractor tests have some kind of brake horsepower per gallon of fuel calculation. Would that give you the information you need?

 

[MechanicalGuy]

I meant, how do their fuel consumptions compare? I don't think I've found that in the documents I've seen.

Burning more fuel at the same (moderate) power would definitely be a disadvantage for higher HP engines in the same application, as several suggested. I just don't know if it actually happens. Does anybody have data?

No one advertises that information, because it's just another way for their competitors to lie and cheat and they don't have to publish it. It would just be a big lying contest.

 

[RickB]

A tua

No one advertises that information, because it's just another way for their competitors to lie and cheat and they don't have to publish it. It would just be a big lying contest.

University of Nebraska and OECD tractor tests are independently performed and impartial.

 

[MechanicalGuy]

A tua

University of Nebraska and OECD tractor tests are independently performed and impartial.

But it's not what people see when they go buy a new tractor. The manufacturers probably don't even reference these tests even if they come out on top. I've certainly never seen a reference to one before your post.

Link me up. I did a search and it didn't immediately gratify me with tractor test results. It was merely a discussion of the intent.

 

[rScotty]

But it's not what people see when they go buy a new tractor. The manufacturers probably don't even reference these tests even if they come out on top. I've certainly never seen a reference to one before your post.

Link me up. I did a search and it didn't immediately gratify me with tractor test results. It was merely a discussion of the intent.

The Nebraska tests are famous and have been for many decades now. They set the standard for measuring tractor performance... worldwide. The Nebraska tests began when farmers realized that they could not count on manufacturers to write honest specs. That said, they are more applicable to Utility and up size tractors than to compacts....but then that's the size we are comparing in this thread.
rScotty

 

[RickB]

Link me up. I did a search and it didn't immediately gratify me with tractor test results. It was merely a discussion of the intent.

Link you up? Figure it out for yourself.

 

[dodge man]

It’s been a few years ago but lawn mower makers got in trouble for selling the exact same engines with different hp ratings that weren’t realistic. For example say a 25 hp riding mower vs a 23 hp machine. Identical engines but to get 25 hp they reved it higher than it was designed to. In the actual mower the 25 hp really made 23 hp because the dialed back the rpms to normal amount. That is why most of the time they list a displacement instead of a horsepower number on small engines.

 

[mo1]

The Nebraska tests are famous and have been for many decades now. They set the standard for measuring tractor performance... worldwide. The Nebraska tests began when farmers realized that they could not count on manufacturers to write honest specs. That said, they are more applicable to Utility and up size tractors than to compacts....but then that's the size we are comparing in this thread.
rScotty

The Nebraska tests are handy as they test fuel usage at varying PTO loads.

Electronically-controlled engines that are otherwise identical except for maximum fuel delivery and maximum turbocharger boost will consume the same amount of fuel at the same power level as they are (drumroll please) the same engine. An excellent example is Deere's 5055E, 5065E, and 5075E engines. They as well as the 5045E that was not tested at Nebraska all are the same electronically-controlled, turbocharged, intercooled 2.9 L 3 cyl diesel (3029H.) They were found to consume the same amount of fuel at similar power levels, but the more powerful the engine, the more fuel it will consume at peak power as it makes more power.