4320 vs 4720

[vsumoski]

Please forgive me for nit-picking AK, but the hydraulic flow was an important metric for me; and Nebraska Tractor Tests pointed out that neither tractor met the 12 GPM specification.

4520
Pump delivery rate at minimum pressure and rated engine speed: 11.3 GPM
Pump delivery rate at maximum hydraulic power: 10.8 GPM
http://tractortestlab.unl.edu/Deere/4520ehydro2.pdf

4720
Pump delivery rate at minimum pressure and rated engine speed: 11.6 GPM
Pump delivery rate at maximum hydraulic power: 11.6 GPM
http://tractortestlab.unl.edu/Deere/4720ehydro2.pdf

 

[AKfish]

Well... that's an interesting bit of information at the very least. However, I'm not totally convinced that you, I or anyone else might be able to distinguish real world performance differences between 11.6gpm and 12gpm.

I'm not attempting to be sarcastic or a smart@ss... I just don't thnk anyone would know unless they utilized the same testing procedures that the folk's in Nebraska did.

That said; I wonder how those differences would play out if you would test 100 different 4520's and 4720's. What would the average deviation from the mean be and what would the mean hydraulic flow be for all the tested machines?

Would it be 1gpm....? Would you or I know any difference?

AKfish

 

[Cidertom]

Did some checking: Yes they are the same pump. So AK is correct, variations would exist across all the the 4x20 line.

One item for thought about the tractors. We have seen the HP discussions. In large scale manufacturing it is not uncommon to have several different models with common theme. While they appear identical, the "lower" models may be constructed with lighter strenght/ weight components, or those that could not pass (by lot testing) the higher power levels. I wonder if any of that is at work with Deere? Common spare parts cannot be used to deny this as it makes sense to stock the parts with the highest rating to reduce required inventory.

And for the record, I think with the 45/4720 HP they could have put a 16-20 gpm pump on it.

 

[vsumoski]

I agree with both of you one hundred percent,
As I said to the OP, "...besides greater horsepower, the only other difference I've been able to discern between the 4520 and 4720 is that the 4720 boasts a higher hydraulic flow."
A skid steer mounted Harley rake requires 13 GPM. One GPM might not matter but what about two? 8k is too much for me to take the gamble.

Harley Rake, Skid Steer, Skidsteer, Power Box Rake M.6H 72" Hydraulic Angle

 

[eepete]

Where do you see the different flow ratings for the 4520 vs. 4720? When I look on line at the web page specifications, they are listed as the same ?

In fact, online the 4120 has the same flow rate

Pete

 

[DoubleTET]

These two tractors use the same frames, seem to have the same weights and overall size.

any benefits to them other than 48hp vs 66hp.

also prices we're looking at is 30k for the 4320 with 400x loader and 33k for the 4720 with the 400x loader.


what are your guys thoughts?

I would consider upgrading to a 400CX loader if you are going to do any amount of loader work.

 

[AKfish]

Where do you see the different flow ratings for the 4520 vs. 4720? When I look on line at the web page specifications, they are listed as the same ?

In fact, online the 4120 has the same flow rate

Pete

He's referring to the Nebraska test results.

Noticed that a number of the tractor listing's on Used Tractors at TractorHouse.com: John Deere Tractors, used farm tractors and farm equipment, Case IH, New Holland, Agco, Caterpillar. have the Nebraska data listed on the bottom of the page. Click it and you can review the test results for that particular tractor.

AKfish

 

[eepete]

Tnx, AKfish. Found the test. What can one say but YMMV

Sorry for reading something (vsumoski), not having it click, then asking

A 7% difference in flow for the 4520 vs 4720. That would be hard for me to tell the difference. It would be interesting to know the variance from unit to unit. But I would suspect that information is closely guarded manufacturing yield related and not likely to see the light of day.
What would be more interesting is to know if flow is a tested measurement on the assembly line, and if so what is the minimum flow to pass a tractor? Again I would suspect it's not tested- each component is either tested or the parts are within some tolerance and that's good enough.

A buddy of mine says "We live in a 3% world" (referring to what sorts of accuracy people can detect). A BIG generalization, I think it varies from 1% (temperature) to 20% (light, volume, horsepower?). But it's good food for thought.

Pete

 

[vsumoski]

Oh, I'm sorry Pete - didn't see your question.

So the $64,000 question remains:
Is 6hp and 7% flow all you get for $3.6K?
Are there ANY other differences?

I think that the 3520 - 3720 upgrade provides 7hp and deluxe seat option for $220 less; what am I missing?

Vince

 

[eepete]

FWIW, I got the 4520 and paid $600 for the better seat. I didn't see the value in the extra cost of the 4720, about $2K. It's probably totally subjective and silly, but I liked the idea of the 4520 running the engine at 10% less than what it could do, kinda like a safety margin. Seat was worth it, power/flow was not.

vsumoski, I should have read and though about what you posted. It's all good, and I learned something!

Pete