Fuel efficiency of John Deere 5075M versus John Deere 5085M

[candersen10]

Does the 3.05 liter engine on the 5075M consume significantly less fuel than the 4.5 liter engine on the 5085M?

 

[buickanddeere]

Info Should be on the Nebraska test site.
Are you looking at efficiency at continuous max HP? Or real world , idling, putting around the yard, driving down the road, start-stop loader work or what?
How many hours of use per year?

 

[smstonypoint]

Does the 3.05 liter engine on the 5075M consume significantly less fuel than the 4.5 liter engine on the 5085M?

See http://tractortestlab.unl.edu/c/document_library/get_file?uuid=f5cec2e9-daae-4908-92eb-67955f2d7664&groupId=4805395&.pdf and http://tractortestlab.unl.edu/c/document_library/get_file?uuid=6275ce5b-fbc4-4327-90c7-432b99bd7979&groupId=4805395&.pdf.

Steve

 

[candersen10]

I was wondering more if anyone had both machines or had used them back to back and found the 5085M to use significantly more fuel.

From looking at the specs it sounds as if the 5085M uses 4.68 gallons per hour at max power versus the 5075M which uses 4.21 (so about 11% more fuel). In the real world does the 5085M seem to use a lot more fuel though? I'd imagine that with a larger more powerful engine you could run it at lower RPMs etc., and wonder if this translates into roughly comparable diesel consumption or a lot more/less?

Thanks so much.

 

[buickanddeere]

I was wondering more if anyone had both machines or had used them back to back and found the 5085M to use significantly more fuel.

From looking at the specs it sounds as if the 5085M uses 4.68 gallons per hour at max power versus the 5075M which uses 4.21 (so about 11% more fuel). In the real world does the 5085M seem to use a lot more fuel though? I'd imagine that with a larger more powerful engine you could run it at lower RPMs etc., and wonder if this translates into roughly comparable diesel consumption or a lot more/less?

Thanks so much.

Lab tests show the tractor's fuel use at max and at 1/2 power as : 5065M 0.410lb per HP per hr & 0.600lb per HP per hr.
5075M 0.423 lb per HP per hr & 0.601lb per HP per hr. lb 5085M 0.436lb per HP per hr & 0.657lb per HP per hr.

 

[MHarryE]

The Nebraska varying power tests (at least for these 2 tests) are run at wide open throttle and varying the PTO load. Most noticeable comparison is at approx 3.75 gph the larger tractor is producing about 10% power. I was surprised to see how inefficient the smaller engine tractor is. Has to be a large price difference or he poorer fuel economy of the 3.05l engine will quickly eat up any cost difference. Neither one of the tractors has very impressive HP-hr/gal numbers compared to our larger Deeres.

 

[MorningViewStables]

Lab tests show the tractor's fuel use at max and at 1/2 power as : 5065M 0.410lb per HP per hr & 0.600lb per HP per hr.
5075M 0.423 lb per HP per hr & 0.601lb per HP per hr. lb 5085M 0.436lb per HP per hr & 0.657lb per HP per hr.

Roughly $2.00 per hour more at full power with diesel fuel at estimated at $3.85/Gal for the 5085M v.s 5075M or about $20.00 every 10 hours at full power.

 

[buickanddeere]

Roughly $2.00 per hour more at full power with diesel fuel at estimated at $3.85/Gal for the 5085M v.s 5075M or about $20.00 every 10 hours at full power.

I'm getting 85 cents an hour difference for a 65HP tractor with 0.436 vs 0.410lb per HP per hr.

 

[Redneck in training]

The most efficient diesel is Vartsila ship engine. Wärtsilä-Sulzer RTA96-C - Wikipedia, the free encyclopedia . The larger is the engine cylinder the more efficient it is. Reason being that the surface of the cylinder (where friction takes place) increases with square of the dimension while volume increases with cube of the dimension. In other words the friction loses of larger volume cylinder increase at lower rate than power increase due to larger displacement.
This works if the number of cylinders for different engine volume is the same. If you add cylinders to increase displacement the friction loses will increase.
Then for tractors the mass of the machine is another factor that affects real world fuel consumption.

 

[JimRB]

What tasks does the poster need to do? My cousin and uncle prepare the fields and plant. Bigger tractors though. If they plow then they are using most of the HP. But they do as much no till as possible. They contract out spray and fertilizer (I think). I think the tractors sit until harvest where they haul grain wagons.

Where I live many farmers make hay with these small under 100 hp tractors. Relatively flat where I live with less than 4% grade so terrain does not eat up a lot of horsepower. Up in PA some terrain can be rather rolling.

Another tidbit about cylinders. It might be a myth. I was told 20 years ago that more cylinders with the same displacement can result in a cleaner burn. Now RIT reports that fuel efficiency is better with bigger cylinders so the question might be what is most efficient for one's pocketbook. A tiny bit less clean running bigger and less cylinders might be better.