Fuel Gauge / MPG Bimini Trip

[cep022]

I've got a SX240 2010 model. I've noticed that the MPG/GPH on my boat is a little bit lower then some of the information published via boattest.com .

I've read information on the gauge calibration but looking at the sensor on mine it does not look at all the same and there is not any adjustment pots.
For example the gauge showed just a little bit under 3/4 of a tank. However when I filled it up and I filled all the way up with too 22 gallons.

Questions being..
1- Anything to check and or do to insure fuel efficiency is max? Silicon places ect?
2- Anyone with SX240 2010 + that's been to Bimini? How much gas was burned to and from? Need extra fuel on boat ?
3 - Is you fuel gauge for 2010 + models off like this ?

 

[Bruce]

When are you heading to Bimini?

I did a lot of fuel calculations based on data from previous crossings in the Bimini 2014-June 22 thread.

This year we crossed on Saturday morning. Afterward we made a run to the empty fuel dock. Then we visited the Sapona and took the boat to the infinity pool. When I filled up on Tuesday I took on 36 gallons into our SX230. I believe I had driven around 70 miles which is right a 2 mpg. We had our family of four plus supplies and too much food for a week onboard. My memory is that the 242s on our trip burned less than I did. We did not have any 240s on the trip this year, only 242s.

My experience is that it is much harder to calculate fuel consumption when crossing the ocean. The waves will greatly change fuel economy. For example my SX230 is supposed to get 3.5 mpg. But in chop in the gulf last year I got less than 1 mpg.

If the water is reasonable for the crossing you should be fine with a full 50 gallon tank.

I believe that your fuel gauge is sensitive to the octane rating of the fuel in the tank and that when it reaches full it is supposed to calibrate itself.

 

[txav8r]

You are also either looking at instant mpg or trip mpg...so the average is skewed, as is instant. Your mpg during a given power setting is what you are after. And your rpm/speed will vary due to conditions, just as @Bruce is saying about the Bimini crossing. So getting "published" isn't ever going to be an exact thing unless you have exactly the same conditions and boat they tested with, but it will be close. I doubt that there is anything wrong with your fuel gauge or fuel burn information...just a variation due to conditions and throttle setting. Going with set cruise rpm's is about the closest you can come to getting max range out of the boat...with one exception. I have not tried this, but I know it is there and I could use it, and might if I had a long crossing like Bimini with smooth water. That would be to set the mode to show gph, and run the throttles up and down slowly to max out the gph's. That would give the best range and give you as close to the test data as possible. Your best range/fuel as well as other settings can be seen here...as you can see, 6000rpm is the highest mpg and speed, but 5500rpm is almost the same on mpg but the speed is slower, so it is a very fine line and will vary. I find frequently that I can't match the rpm to that as the conditions don't permit it, so I get what I get. But I try to stay between 5000 and 6000 regardless, and optimally between 5500 and 6000...unless it is dang smooth, then it is WFOT! Excuse the profanity.

 

[cep022]

Thank you for the replies. Planning sometime 2015 June / July. The dates have not been confirmed or nailed down yet.