That is fine, but if you have a source for where this comes from I would actually like to see/read it, as it is contrary to everything I have ever heard.
All an engine does it turns heat energy into movement energy. In a diesel engine it turns it into rotating mass. I'm just not understanding how so much additional energy is used to power a nearly identical amount of rotating load simply by doubling the number of cylinders.
After reading through this... I'm going to agree with what you are saying.
A 4 cylinder compared to a 2 cylinder with the same load applied to both will get roughly the same fuel economy.
Lets think it through a bit. The specs claim the 4 cylinder version uses twice the fuel. That is because it is rated at full load. Both units are.
If the 2 cylinder unit is at full load, than the 4 cylinder unit is only at half load to provide the same amount of power output. Keep in mind both have the same injectors.. same pumps.. etc. 2 injectors firing at full flow... is the same as 4 injectors firing at half their rated flow. A 2 cylinder engine at full load... is making the same power as a 4 cylinder engine at half load (all other things being the same). Now you do have added rotational mass losses from the added cylinders... but its negligible. The 4 cylinder engine isn't working as hard as the 2 cylinder to do the same amount of work... it's working half as hard... meaning it only needs half the fuel it would need compared to running at full load.
For instance... an injector flows 100cc at full load (bs numbers). 2 injectors... full load... 200cc of fuel into the cylinders.
Same 100cc injectors... 4 injectors.. half load... half the flow. 50cc x 4... 200 cc of fuel into the cylinders.
Yeah there are more variables... but mechanical diesels tend to not care too much about variables. Load = fuel usage.
From all the reading I've done... my MEP-003 will consume ~ 1/2g per hour at 50% load. These are real world usage numbers. That happens to nearly match the specs for full load fuel consumption of the MEP-002.
But anyways.. good thread! I've always liked the idea of moving to Alaska.. just can't bring myself to do it. I'm an IN native too.