Choosing HP rating in a specific tractor lineup?

bam747 · Apr 23, 2005

This question is not about picking a specific tractor horse power rating but picking a specific horse power rating within a specific manufacture's class lineup of tractors.

For illustration purposes, consider the new lineup of John Deere 4020 series tractors. With eHydro HST transmissions, 4020 series tractors are available with PTO ratings of 35 (4120), 40 (4320), 45 (4520), and 50 (4720) horse power using manufactures published specifications.

All tractors appear to have the same 149 cu. in. 4-cylinder turbocharged diesel engines. All tractors are listed at exactly the same dimensions and weight of 3,700 lb. All tractors have the same hydraulic systems (pump capacity, 3-point lifting capacity, number of available SCVs). All tractors have the same size fuel tanks. All tractors have the same size tires. All tractors accept the same FEL. All tractors have the same...

In other words, except for the published horse power and torque ratings, all four John Deere 4020 series tractors appear to be identical.

When I've asked this pointed "What's the real difference between all the 4020 series tractors?" question at several dealers, I get an immediate response of "It's the horse power". Well, that and approximately a $1,700 to $1,900 bump up in price per 5 PTO HP!

Since a tractor is generally a very long term purchase, usually measured in decades for personal use, why wouldn't you buy as much horse power as possible in a given tractor series?

The one concrete reason I can come up with is fuel use. Given the same engine, like in the 4020 series, the only way to get more HP is to squirt in more fuel and air. Hopefully, with modern engine controllers, they are smart enough to know not to squirt in as much fuel and air when it's not needed yet can max out the motor when it is needed.

The big dilemma as I see it is that if you buy more horse power, I see very few occasions when I would say "Dang, I wish I had less horse power". Conversely, if you buy less horse power, I see many occasions where you probably say "Dang, I wish I had more horse power"!

_RaT_ · Apr 23, 2005

Probably a smart move on JD's part to offer basically the same engine with increases in HP being a primary consideration. If your hooked on their product and really want it, you will be faced with the obstacle of just how much HP do you need and will you be willing to spend the extra to get it. Doubtful that the increase in HP has a corresponding increase to produce it but they do have you hooked. Perhaps they are also counting on countries like the US where folks in general lust for powerful engines and can expect those individuals to go up in HP whether they need to or not. We are already seeing posts here on how to up the HP on the less HP models.

Bob_Skurka · Apr 23, 2005

<font color="green"> The big dilemma as I see it is that if you buy more horse power, I see very few occasions when I would say "Dang, I wish I had less horse power". Conversely, if you buy less horse power, I see many occasions where you probably say "Dang, I wish I had more horse power"!
</font>

I think the HP issue is generally decided by the PTO powered implements you need to run. Within any given frame size, I generally favor the most powerful engine available as it often is the best value for the dollar (not always true, but common enough). So to compare some other machines, in the NH line up, there is the TC23 and the TC26 (formerly the TC21 & TC24). I'd only consider the upper end engine as it would have the PTO power to run a slightly larger implement . . . or it would have the reserve power for a similar implement when the going gets tough. Similarly, NH offers the TC29 and the TC33. And again the TC35 and the TC40. Switch over to the Kioti line and take a look at the CK25 and the CK30, same frame, 5hp difference. There are plenty of examples of what JD is doing across the different manufacturers. Generally the lower hp tractor may be a decent machine, but the upper hp machine is generally considered better.

MF85 · Apr 23, 2005

I'm throwing this out there because it is related, and I'm fishing for comments: My dealer is saying all I need is the 4120 for the work I am doing (grading and leveling RV park and campground sites and roads with a Grouser Belly blade). Grouser said 35 HP was required. Others said I lose 3% HP with every 1,000 feet of elevation (I'm just over 6,000 feet) so I should get a 45HP to net 35. When I told this to my JD dealer, he said because the 4120 is turbo charged, my net will be 35 with a 35 HP JD tractor, unlike others.

Comment?

He's also quoting me for something called a JD "Power Beyond Kit." I have not asked him what that is yet. Is the a HP booster?

Thanks.

Bob_Skurka · Apr 23, 2005

Power beyond is part of the hydraulic system, it allows you to power something "downstream" of the valve for future expansion to add something like a hydraulic top link or a Top N Tilt system.

I have no clue about the JD dealer's hp claims on the engine. I also don't know if it is true that you will lose as much power with the altitude that you have been told you will lose.

bam747 · Apr 23, 2005

The JD dealer is correct about HP loss versus altitude. The general rule of thumb is that naturally aspirated engines loose 3%/1000 ft. while turbo engines loose very little to 1%/1000 ft. This gives turbo engines a significant advantage over like HP rated naturally aspirated engines at altitude. You can see more discussion on this at this thread:

http://www.tractorbynet.com/forums/showflat.php/Cat/0/Board/buyjd/Number/542497/page/0/view//sb/5/o/all/fpart/all/vc/1

Hydraulic "Power Beyond Kits" give you easy hydraulic connections (source/return) to allow connection of equipment like back hoes or log splitters which have their own control valves.

tjkadar · Apr 26, 2005

HP is not always the defining factor in a tractor purchase. One should always consider the job they want to perform, the implements they would like to use, and then decide which tractor best suits that need. Often times, you might be purchasing more HP, but you aren't getting anymore tractor. In reality, your implement might not need more power, but a bigger frame and weight on the tractor.

For example, the Kubota M4900 and M5700 is the same tractor. The M5700 spins a bit higher and has more fuel shot to the engine in order to get more HP out of it. They also put on 2" bigger tires, but that is the only difference between it and the M4900. At this size, you really aren't stepping up from the M4900 to the M5700. About the only thing you are doing is spending more money.

If you look at the specs, the M4900 and M5700 are essentially the same. Same lift capacity, same total pump output, etc. The M4900 is going to be able to do anything the M5700 will do. All you're doing by buying the M5700 is spending an extra $1,300.

To make a true step up, you need to move to a M6800. This may or may not apply to the JD lineup.

I doubt I was very clear in what I was trying to say. If not, I apologize. If you can decipher the jibberish I wrote, then take it into consideration when buying a tractor.

More HP does not always equal more tractor.

Highbeam · Apr 27, 2005

Given the same engine but with the available power restricted I would suggest that the engine will live an easier life and last longer. If the engine and drivetrain can handle 40 HP and you only are producing 30 HP then all of the downstream items have been effectively overbuilt and should offer longer lives.

Less fuel consumption too.

The OTR truckers have a similar deal. You buy a 250 HP tractor and you can have the HP bumped electronically. The fleet managers like less HP for durability and less fuel consumption but the truckers want to hurry up and get home.