Hp.hr/gal

[manuel molinar]

Please define HP Hour/Gallon

 

[RickB]

The number of horsepower that can be produced for a full hour using one gallon of fuel.

 

[MHarryE]

Lots of people brag about how little fuel their tractor uses but usage is really dependent on load. For example I am looking at a tractor that uses 9.6 gallons per hour at max engine power but that is 17.98 HP hr/gal. If that same tractor is pulling a smaller implement and therefore is running at only 75% of its max power, it gets 13.98 HP hr/gal. It is using 8.1 gallons per hour so less fuel per hour, but the engine is not running as efficiently at this low power. It is pulling at 75% max power but it is using fuel at 85% of the max rate. I saw a big difference when I swapped my L3710 for a L5740. I use many of the same implements and am therefore running lower on the power curve than I did with my L3710. I burn significantly more fuel to do the same work, but on the other hand I do have the extra capability when I need it.

 

[90cummins]

It's call brake specific fuel consumption or (lbs/hphr)
Meaning hp at the crankshaft with no accessories.
Most industrial diesel engines will give the specific fuel consumption at various engine speeds and hp.
Lets say my 1990 Dodge Cummins operating in it痴 sweet spot had a specific fuel consumption of .34 lbs per hp/hp hour.
If the engine was developing 65hp then you multiply 65x.34 = 22.1 lbs of fuel consumed in 1 hour now divide that by the weight of the fuel which is approx
7.1lbs and you get 3.11 gph consumed.