Question for Diesel Geeks

[BobT]

I've been thinking. My Allis-Chalmers 190XT Series III is full-load rated at 2400rpm. When I'm using it under load, such as plowing or field cultivating, is it best to use it at full throttle or should I back off just a bit? As I've been researching this question 1800rpm seems to pop up quite a bit.

Anybody have any expertise or thoughts about this? If I can improve efficiency I reduce atmosphere emissions and save fuel cost at the same time.

Thanks.

[Powerstroke]

Most diesel motors reach peak torgue very low in the RPMS and then reach max HP within 85-90% of top RPM.

I would think you would want to run a little lower RPM. You'll get all the oomph and still allow you more RPMS to use in case you need to help power through something. I'm not super familiar with your tractor but I know when I'm working on our tractors at work I run 14-1600 RPMS with the proper gear on the tranny.

[MJ1657]

As long as you aren't lugging the engine excessively with the lower rpm's I would throttle back.

Try it and see how many hours you can run on a set amount of fuel.

[BobT]

The equipment I use doesn't overload the tractor so cutting back on the rpm's a little won't be much problem. I might give it a try this spring when I start tilling and see how it goes. Thanks.

[MJ1657]

I bet you will see big gains if you aren't running them hard.

We plant and chop stalks with a 4440 John Deere. We plant like I said around 1600 rpm's and we chop stalks full throttle which is around 2200 rpm's.

We have to run it wide open to have enough rpm's on the pto to chop stalks thoroughly. It does take a little more power than pulling the planter but not alot.

Fuel consumption is alot higher while stalk chopping but I do not know an exact number.

I will add that 4440's are not known for being very fuel efficient. When they came out that was not a big concern for most farmers.