Fuel efficiency in old versus new diesel tractors

Some of the newest tractors have broken fuel-efficiency records at certain power levels - mostly new Deeres. However, those figures drop like a rock at lower power levels.

Previously, I thought the old Nebraska tests did not check for fuel efficiency at lower power ratings - but I just found out they did. My 1951 Tractor Field Book has complete tests for all tractors that year. Here's a comparison of a 1951 Deere R diesel two-cylinder, with a modern Case-IH CX 50. Efficiency expressed in HHGs - i.e. horsepower hours per gallon.

Deere R diesel 1951: At 43.5 horse it tested at 17.6 HHG At 33.5 horse it tested at 17 HHG At 26.5 horse it tested at 15.5 HHG At 11.3 horse it tested at 11.1 HHG At 1.6 horse it tested at 1.5 HHG

Case IH CX 50 1999: 42.5 horse at 15.2 HHG 37 horse at 14.8 HHG 28 horse at 13.5 HHG 18.9 horse at 11.1 HHG 9.5 horse at 7.9 HHG

Now, also look at the Deere 8520 that is one of the most fuel efficient tractors tested.

Deere 8520 tested 2002 292.8 horse at 18.1 HHG 113 horse at 13.2 HHG 56.7 horse at 11.3 HHG 1 horse at 3/10 HHG (pretty bad)

I used to pull a six row cultivator with a 1070 Case, which was almost an unnoticeable load. I usually ran half throttle at the most. Then I traded the 1070 for a 1086 IH and when the 1086 pulled the same cultivator it used more fuel per hour. Under a full load was a whole different story, with the non-turbo'd 1070 using about the same amount of fuel to get 108 horses as the turboed 1086 did to get 135 horses. The difference might also have been because they were two different breeds of animal from the ground up instead of just turbo/non-turbo. Jim

Rod

I just read through some archives, and when the New Holland 8870 was tested at Nebraska asking Deere and Case, it lost to both and it was nowhere near 20 horsepower hours per gallon. Here's a piece of the article:

From Farmers Journal 1998 : "In the Nebraska tests, the New Holland 8870 were compared
with equivalent models from John Deere and Case. Across four models, the New Holland fuel
economy figures were coming in below the others in each sector. The differences ranged from
11 per cent for the smaller models to 13 per cent for the bigger ones."

And here's one about Deere breaking the fuel-efficiency record - which they broke again this year:

Fuel Efficiency Record Set By John Deere 8430 Tractor In Nebraska Test Lab LENEXA, KS (July 14, 2006) — John Deere recently tested an 8430 Tractor, rated at
250-PTO hp, at the Nebraska Tractor Test Lab in Lincoln, Neb. to independently verify fuel
efficiency, power, and performance. Record-setting results were returned for fuel efficiency on
the 8430 Tractor with Automatic PowerShift Transmission (PST) for power produced to fuel
consumed of any row crop tractor ever test
The tractor was equipped with an Automatic PowerShift transmission and tested at 100 percent
PTO load at rated engine speed. The record result of 18.65 Hp.-hr./Gallon was achieved.
Previously, the 8520 Tractor with the same equipment had test results of 17.13 Hp.-hr./Gallon.
This 8.8 percent improvement is now the benchmark for tractor fuel efficiency performance in a
row crop tractor.

I'm on my way out the door in a few minutes, so I won't look until tomorrow.

Rod

Newer engines turn at a higher rpm to get the same HP, more rpms = more fuel...

They clanked,they rattled, and the pony start was kind of a complicated PITA, but they sure could squeeze a lot of work out of a gallon of fuel.