Fuel Consumption

[connie garcy]

99 Sundancer 370 with 7.4 Multi-Port fuel injectors. Does anyone know at what speed/RPM would give us the best fuel consumption. I have seen post for the 95 Sundancer 370 but we don't know if they had the 7.4 Multi-Port fuel injectors.

 

[Gofirstclass]

Connie, the rpm/speed is going to vary a bit depending on your load of people, water and fuel.

Rather than suggest a specific set of numbers, let me suggest a method of determining that for yourselves. Here's how....when you are going to go from idle speed to being on plane, push the throttles all the way forward. That gets the boat quickly up and over that transition point where it goes from being IN the water to being ON the water.

Once the bow comes down you've made that transition and it's time to pull the throttles back. Slowly pull them back and listen to the engines. When they sound like they're struggling to keep the boat up on plane, add a bit more throttle. Play with the throttles a bit until the boat "sounds good". It takes just awhile to recognize that sound, but when you hear it you'll recognize it. That is the sweet spot for the boat.

Once you get into that sweet spot then play with your trim tabs a bit. Keepiing an eye on the gps, trim the boat up a bit, then down a bit and see what effect each tab adjustment has on the speed. You may see the speed increase a mph or more when you get it trimmed our.

I hope this helps!

 

[mquiet]

I think the rule of thumb is best cruise is 0.6-0.8 for any boat. I had a gasser 340 what got 0.75mpg when cruising. My buddy got 0.7 in his 500 sundancer. We travel at different speeds but the rate is the same. Enjoy the new boat, but don't focus on the fuel as the cost will be high, but the adventure and memories are worth it

 

[JVM225]

The numbers on boats can flucaute greatlly with weight of load, and conditions.
I've found the best way to ave fuel on a powerboat is with a fuel flow gauge or meter of some kind. Something that not only tells you how much each engine is burning at any given moment, but also computes a MPG for you is best, but if that isn't in the cards, at least get something that tells you what you are burning.
The pther upside to fuel flow gauges is that you can easily comput how much fuel you have aboard.
I've foud the two most usless things on a boat are the windshield wipers, and the fuel (how much is in the tanks)gauges.