Fuel burn qsb 5.9 380's

[Mike Mason]

Is this accurate in what I should be seeing for fuel burn. If so I may be over propped. I see 8 gph per side at 2000 rpm and 10 gph per side at 2200

This is fully loaded with bait tanks full and all the gear. 4 guys

Boat is a Tiara 33 flybridge

Topic

[Bill Desmarais]

The fuel burn numbers of an identical engine @ say 2,000-2,400 rpm will obviously vary in different hulls.
It’s all dependent on how much hp is required to move a hull in the water at a given speed.

I’ll make a guess that a 33 Tiara is “on the hump” plowing water getting up on plane @ 2,000 rpm. Takes a lot of hp to get a big planing hull up on plane. Once on plane……takes less hp to push the hull.

Example:

I’ve owned five 6BTA 370s. More or less the same hp/fuel burn engine as the QSB 380.

The pr. of 370s that were in my former 31 Blackfin combi burned 8-9 gals each cruising @ 22 knots @ 2400 rpms.

The single 370 in my 25 T Jason lobster boat burns 5 gals/hr. @ 2,600 rpms running 22 knots.

Why?….the 25 footer is much easier to push thru the water @ 22 knots…..the 31 Blackfin took lots of hp to push the hull @ 22 knots.

Just my two cents

1 user thanked author for this post.

David R Flamer

[David R Flamer]

I’m running 10.5-11 GPH per side at 2,200. 15.5 kts typically

[Fireisland1]

I’m running 7.5 GPH/2000 . Single clean

[Mike Mason]

We like to cruise at 2150-2200. 18-20 knots.

[Rob Schepis]

I doubt she is on a clean plane at that low of an rpm?

What rpm is your cruise speed?

[Author]

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