Vintage John Deeres - Weight vs Power

[chetlenox]

Hey all,

My father-in-law and I were discussing the differences between the vintage (40s-50s era) model numbers of John Deere tractors. I put together the following plot that shows the weight vs horsepower for the last model year of each model name. Horsepower is the gas version at the drawbar. If there was only a diesel version, I used that number. Figured I would post the data for entertainment value.

FYI: The datapoint for Christy (my wife's) 4520 is shown just to show how new compact tractors don't exactly "fit the curve" of these older Ag tractors.

I also drew dotted lines at 2 tons and 35 hp, which seems to be most folk's description of the minimum tractor required to run a small square baler.

Chet.

 

[EquipmentJunkie]

That is interesting data.

It is also worthy of noting that a lot of newer compact tractors (including the 4X20-series) are built on common frames and the weight is virtually identical no matter the horsepower within the common frame. In other words, a Deere 4120 tractor would appear directly below your wife's 4520 and a 4720 would appear directly above it.

 

[chetlenox]

Yep, you are right. 4720 adds 5 HP, 4120 subtracts 10 HP, weight doesn't change a pound (according to the specs).

To me it was just funny how far "off the curve" our little compact tractor is. It might be interesting to see where the new more Ag-targetted JD tractors hit the curve (5xxx, 6xxx, 7xxx series). I'm guessing they would probably still be the same distance vertically (up the y-axis) from the vintage-era curve, just farther up in weight than our compact. Maybe I'll add some in when I get a chance just to see.

Chet.

 

[Wayne County Hose]

You can't go by horsepower. It's torque that moves things. Those old 2 bangers had enough torque to move a mountain. I had an A, B, and a 50 and I'm willing to bet that any one of them would pull most new tractors the same horsepower all over the mountain.

 

[wolc123]

Weight is directly proportional to the traction force a tractor can develop. Horsepower and torque dont mean much if you cant put the power to the ground. My neighbor has a 4720 and I have a 4120 with loaded tires (his are not loaded). My tractor will move dirt much faster than his in spite of much lower hp and torque because the extra weight lets me engage most of my available power, while his merely spins the wheels. Tractors on that curve your graph shows are optimized for getting work done. Those above it are optimized for ease of sales to uneducated consumers.

 

[chetlenox]

Ha!

Easy boys, I wasn't implying any sort of "inferiority" for the older Ag tractors, just posting some historical specs for entertainment value. I would also hazard to guess all those "uneducated" consumers you are knocking don't really need to do a whole lot of heavy groundwork (ie, not so uneducated, they are buying the right equipment for the job).

Doesn't change the fact that ya'll are both right on with your torque and weight points. Me personally, I think I'm going to go with something in the 5000 pound area (A, 520/530 region) as my backup baling (and hay-ride for the kids) tractor. At least that's my goal.

Chet.

 

[slowzuki]

Replot with drawbar hp for your wifes machine and it will fall right in line.

Ken

 

[Wayne County Hose]

Chet,

I didn't think you were saying anything about the older stuff being inferior. Really, it's the manufacturers. Them old "letter" tractors had so much torque I think they could change the rotation of the earth. What's funny too is that we never had a 4 wheel drive tractor on the dairy farm and never got stuck either. They made them way different back then.

 

[Soundguy]

Chet,

I didn't think you were saying anything about the older stuff being inferior. Really, it's the manufacturers. Them old "letter" tractors had so much torque I think they could change the rotation of the earth. What's funny too is that we never had a 4 wheel drive tractor on the dairy farm and never got stuck either. They made them way different back then.

I own a bunch of 2wd tractors now.. most antique.. some classic.. one new... some big, some small only a couple with diffy lock. The only tractor I have ever been stuck in was a new CUT 4x4 with diffy lock... I don't own it anymore...

soundguy

 

[wolc123]

Back when all I had was 2wd, I could never finish spring plowing until mid June or so on my mucky bottomland farm. Now, with 4wd, I always finish at least a month earlier no matter how wet it is. Fuel consumption for tillage is also down around 25%. I have not been stuck in the 3 seasons I have had 4wd, and would get stuck 3-4 times a season on average with 2wd. In my humble opinion, 4wd is the only reason to buy a new tractor.