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Old 07-23-2011, 04:52 PM   #13
Delfin
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RE: Fuel Economy Question

Quote:
FF wrote:
For example, a Cat 3408 displaces 18 liters, and burns 11.7 gph to produce 216 hp, max HP 536.

Comes to 18.46 hp/gal

A Cat 3306 displaces 10.5 liters and burns 12.1 gph to produce 215 hp, max HP 270.

About 17.7 gal/hp

The problem is this is the full , max power output , where the engine IS efficient.

Reduce the power output at the prop to 30- 40hp and 8 to 12 HP/Gal may be the result.

That is why (proper loading) CPP props are on the commercials and cruising props on the distance cruisers.
*Emm, not so much.* I am right now moving along at 1300 rpm, prop demand hp of 56, burning 3.4 gph or 16.47 HP/Gal.* Some drop off in efficiency, but certainly not enough to worry about.
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