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I'm under the impression they are but both suck!!! On a twin engine V bottom it's probably from 1.2 mpg to 1.4 mpg at cruise....my motors are built and get closer to 1.0 to 1.1 even though they are EFI.
 

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Sometimes, but sometimes not. It depends on how close the tune is on the fi vs the carb for the same motor.

THat said, if the tune is halfway close, the engine should not be pinpointed as the fuel effeciency issue.

The issue would be the boat - including propping, most effecient running speed and attitude, driver's awareness of this, and etc.

Furthermore - boat design/weight itself. Some boats take way less power to cruise at certain speeds vs others. The more power you use or have to use, the more fuel you burn.

Worst mpg ? Idling in neutral. Why ? Your not going anywhere so miles per gallon = 0. :laugher: :laugher: :laugher:

PS: Don't forget the more weight you add (fuel, people, gear, etc) can have a big effect as also how you use the drive trim and tabs.
 

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From what I have read the biggest difference in fuel consumption will be in the mid-range as the EFI motors are constantly changing fuel, timing, etc.
 

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Figure it like this.

Take a 300 hp fuel injected motor and a 300 horspower carb'd motor.

As blackhawk said during cruise the computer can calibrate itself real time to give the motor what it needs, the carb can't. so the FI will get better mileage.

At WOT they both are going to have to feed 300 hungry horses so the difference will be minimal.

To take it even further take a standard TBI motor and compare it to multi port injection motor and you will see the same thing. The TBI acting more like the carb'd motor.

All of this of course is assuming the same boat, weight, prop, etc.
 

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I disagree UP_ROKTOY.

Calibrate itself ? Kind of but not as much people think. Does it really watch and control A/F ratio ?

Carbs can do a tremendous job metering fuel. Many don't give them enough credit, then again, some give them too much credit. LOL.

Boats are different from cars, therefore we need to treat them different along with our facts/theories/and opinions. Some are true and can be interchanged of course.

How is tbi like a carburetor ? It has injectors, computer, and sensors. It does not have boosters, fuel metering orifices, floats, needle's and seats, or anything else like a carb that has input on fuel delivery. Just because it mounts in same place as carb does not mean it's the same.

You can say that it typically uses carburetor or carburetor type intake manifolds though.

Just in case you think I'm pushing buttons I'm not. Just throwing some info out there. :D You've had enough excitement here recently. LOL.
 
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