fuel consumption

[khemberger]

Can anyone tell me at what rpm setting I will get the best fuel
consumption for estimating range. I own a model 320. Thanks.

 

[navigator97]

For a Yanmar 2GM20F Diesel engine, it's close tp 2650 RPM for the least GPM value.

 

[Steve Dion]

I would be much more concerned about protecting the engine than the fuel economy. Check out Yanmar Help for advise. You should operate your engine within the guidelines of the manufacturer. Low RPM will shorten your useful engine life, but you will not spend as much on fuel, so maybe you will more money to purchase a rebuild or new engine.

You also need to be sure that then bottom and prop are clean to optimize fuel economy and achieve max. speed with the lowest fuel consumption.

 

[Benny]

You cannot estimate range from fuel consumption. You can estimate the time the engine will run but range will vary with conditions out in the water and will be mostly influenced by current, wind and the drag induced by the hull. Our h320 is equipped with the 2GM20F and we have calculated our burn rate at .42 gallons per hour. For calculations we use .5 gph for convenience as well as obtaining conservative figures. Our tank is 25 gallons of which we consider 23 to be usable as with sea motion the engine may start sucking air before the tank is empty. We also factor in another 3 gallons as an emergency reserve. So now we have a self imposed usable capacity of 20 gallons which will give safely give us 40 hours of motoring. Range can be calculated on the water, on the day of travel according to bearing and conditions encountered. It has been our experienced that more refined calculations at set RPMs are not really necessary for keeping track of fuel utilized and scheduling refueling stops.

 

[khemberger]

Thank you so much for your very knowledgable reply. I was also interested
in the best rmp setting for cruising.... any thoughts. Ken

 

[khemberger]

Thanks so much for the very knowledgeable reply. I was also interested in the best
rpm setting for cruising.... any thoughts? Ken

 

[Jerry Clark H356 SV Persi]

Cruise at 75 to 80% of max RPM

Take your boat out and find your max rpm. All are a little different due to the prop etc. Use 75 to 80% of max to cruise. That is what is recommended by Yanmar.

 

[Steve Dion]

The standards for operating your engine ranges from 70-80% of the max rated RPM. Assuming that you have a 2GM which is rated at 3600 RPM Max you would be look at somewhere between 2500-2900.

http://www.yanmarhelp.com/index.htm

This site has a lot of good information about the Yanmar engines.

Review this site and save it. It is a good place to find references