Cat C12 fuel burn?

[soin2la]

A 55 foot, 38GT (26Net) with twin Cat C12s is claiming 7-8 litres per mile at 18kts (126-144LPH). Does that seem realistic? Per side maybe?

 

[rslifkin]

If it only measures 38 gross tons then that must be a pretty skinny 55 footer which would help efficiency (and I could see 2 gallons / mile being possible). What's the actual weight on it?



FWIW, my (not light or narrow) 38 footer with inefficient old gas engines gets about that same fuel economy (just under 2 gallons/mile) at ~17 kts.

 

[soin2la]

This is a registered passenger vessel, and so bare bones Interior.
Registered...

L 15.88m

B 3.09m

D 1.32m

GT 38.41

NT 26.22

 

[tiltrider1]

Is this a factory marketing claim? I see manufacturers go out with a base boat, no fuel, no water, no options, no people and then make a one mile run only measuring fuel consumption after the boat is up on plane.

I call this real world lying. Or lying with statistics.

 

[soin2la]

Owner's claim, over time with an average of 40 passengers.

 

[rslifkin]

Those numbers equate to only a 10'2" beam. That's very skinny for the length. So depending on how heavy the thing is, those numbers might actually be in the ballpark. Of course, if that's all it's burning, the C12s are probably much more engine than it needs for 18 kts and it can likely go a good bit faster.

 

[sunchaser]

S
A peek at the C12 curve suggests the claims are in the ball park. As a verification, most properly setup Cat C12s have the ability to give a readout as to fuel burn both over time and instantaneous. A fly in the ointment could be lots of idle time building up hours at a negligible fuel burn.

 

[soin2la]

A fly in the ointment could be lots of idle time building up hours at a negligible fuel burn.

A good point. One third of it's current daily operating is at 5-7 knots.

Thanks everyone.

 

[vacser]

My 54ft with C-12s burn 40 gallons per hour/ 20 gallons per side at 18kts. She weighs 54,000 lbs full. At 8 kts I burn 8 gallons or 1 mile per gallon

 

[soin2la]

My 54ft with C-12s burn 40 gallons per hour/ 20 gallons per side at 18kts. She weighs 54,000 lbs full. At 8 kts I burn 8 gallons or 1 mile per gallon

Excellent, thank you.

 

[tiltrider1]

My 54ft with C-12s burn 40 gallons per hour/ 20 gallons per side at 18kts. She weighs 54,000 lbs full. At 8 kts I burn 8 gallons or 1 mile per gallon

The 1/2 mile per gallon at 18kts sounds pretty normal. The 1 gallon per mile at 8kts doesn’t sound right. I would think you could travel at 10kts. At 8kts I would think you could get 1.25 miles to the gallon.