A Comparison of Fuel Consumption of Yamaha Boats

[Bruce]

This is motivated by predicting Bimini crossing fuel consumption but should be of interest to all boaters as it includes maximum range for lake conditions as well.

I started with the BoatTest.com fuel consumption numbers. In the past I have looked at these based on RPM but RPM does not translate well across different engines. So I decided to interpolate range values for fifteen models of boats every six MPH from 12 to 48 MPH. I simplified the process by limiting the data to one version of each hull and engine combination. For example the 2015 Limited was chosen to represent all 2015+ 240 and 242 models. The result of which is this chart




From there I wanted to be able to provide an estimate of range in Gulf Stream crossing conditions on the way to Bimini. To do so I extrapolated fuel consumption based on a 2015+ 242 having a fuel range of 56 miles at 18 MPH. This is consistent with some needing fuel a few miles from Bimini Sands while others made it into port after the 58 mile crossing in 2017. Here is the extrapolated data. As a test this method predicted my 2007 SX230 to have approximately a 78 mile range under the same conditions where my observed range was 79 miles. Here is the result



Furthermore I wanted to limit the data to just the boats in my group. I believe this explains why Chris24 (2014 212ss) and I (2007 SX230) had plenty of fuel while Betik (2011 SX240), Watergirl (2011 242 LS) and and @hobineros (2016 242 LSE) made it in on fumes.



I have attached a spreadsheet with the raw data if you would like to add another model or improve upon the results.

 

[spatty99]

Great analysis. Certainly seems like the 1.8 was a step back in efficiency?

 

[seanmclean]

Man, I thought the current 242s were a lock for fuel. Seems like it could be a little close for comfort with a rough crossing.

 

[Scottdip]

Is it possible to add the Scarab line up to that graph?

Would love to see that comparison.

 

[BigAbe75]

I'm not sure how you could account for this variable, since they are likely all different... but what's the current theory regarding impact of trim tabs? Better or worse for gas mileage?

 

[Betik]

@Bruce this is great stuff. Depending on what data is available, I can probably forecast consumption for individual members. If works out, a user can log in his or her personal data and get an estimated range.

I will put something together for myself and upload it as sample.

 

[Bruce]

@BigAbe75, trims tabs likely decrease efficiency as they add drag.

@Betik, I did the interpolation in MySQL. I can give you access to that database if you would like. I am considering converting this to a web graphing tool from excel.

 

[Betik]

@Bruce I will need to build a sample excel and share with you to see how physible it is to collect the data.

@BigAbe75 trim tabs will be one the components and i should be able to tell you if the impact is significant or not. If it is then tell you impact ( reduction in range due to trip tabs). Best case scenario I should be able to see the impact by percent deployment. This last one is too granular and I doubt that people remember trim tab % deployed, but I will build it in the excel just in case. Who knows maybe 2018 becomes a laboratory and in 2019 the moment we exit port Everglades and see the wave height and determine the minimum speed needed to arrive safely in Bimini.
Once we have a reliable forecast I can build scenarios and prescriped actions.

 

[swatski]

Great analysis. Certainly seems like the 1.8 was a step back in efficiency?

Nah. I think the MR-1 guys just have a more steady hand! (lol)

But seriously there are way too many factors, not even the same person testing, and once you start playing with throttles - all bets are off.

To make it meaningful one would need to do the testing under same condition/in various boats equipped with something like RideSteady (for perfect engine synch, too).

--

 

[Jgorm]

Is this data collected, or mfg specs?

 

[Bruce]

Is this data collected, or mfg specs?

I used BoatTest.com's smooth water two person, half tank test data as the starting point interpolating the 12 to 48 MPH maximum range from their numbers.

 

[Bruce]

@swatski is right that driving style, boat condition, weight of boat and water conditions make too much of a difference to accurately predict fuel consumption for something like a Bimini crossing. For example, while many 2015+ 240/242 models needed extra fuel to make the 2017 crossing Swatski arrived with 10 gallons remaining in his tank.

In the past I have used lower precision estimates. This data allows for a better understanding of which boats are likely to need fuel on a Bimini crossing.

I believe that Betik wants to gather multiple points of data from those making the crossing on a large scale to even more accurately predict consumption.

 

[hobineros]

Better add in a factor for the speed of the Gulf Stream pushing you ~5mph to the north

 

[Ancient canoe]

Is that the older non HO MR1 at the top of that graph? If so, I don't really understand why Yamaha decided to replace it with the TR1.

 

[zipper]

@Ancient canoe I believe the boat on top of the graph is @Bruce 's 07 sx230 which has H.O. MR-1s. There was probably nowhere left for Yamaha to go with the 1.1L MR-1s. They are a high compression 11.9-1 motors that would not like boosting with superchargers etc. They spin at 10,200 rpms WOT and can be noisy. The 1.8s opened up a new platform they could build upon.

 

[Bruce]

The top green line is the 2007 SX210. The second highest, orange line, is the 2012 SX210. The 2007 SX230 comes in third at the purple line.

Interestingly the 2017 TR-1 powered SX210 is in the lower half of the graph with a max range of 130 miles.

 

[Ancient canoe]

That is what I thought. Seems like the old non HO MR1 was much more efficient than it's predecessor TR1. Not sure why Yamaha pulled the plug on the MR1. Maybe the TR1 does better in other vehicles but just not boats?

 

[zipper]

@Bruce Sorry, mixed up the two colors between the 210 and 230, it makes sense being a smaller hull with the same H.O. engines.

EDIT: Was schooled and the 07 210 had non HO MR-1s

 

[Jgorm]

They probably switched because people want more hp and torque. The mr1 is gutless down low. Boost is the way everything is moving for weight, economy, and emissions. I believe it's the hp wars on the jet skis that is driving engine development.

 

[Bruce]

H.O. engines

The 210 models had a non HO version of the MR-1. That engine was an option on 230s before 2007. It is interesting that those lower powered engines are the most efficient.