Westerbeke 10hp on Oday 272

peterbud · Apr 8, 2009

Pat, I had that same engin in a catalina capri 26 5000lbs so it is close to your boat and motor. I went from cuttyhunk to falmouth Ma. in 6 plus seas with no problem and had plenty of fuel when I pulled in. I bellieve my tank was 10 gallons.

Ross · Apr 8, 2009

I run a ten horse Volvo in my Islander 30 and figure about 15 mpg. at about 5 knots. The fuel consumption rate increases exponentially with the speed. You can go a lot farther on a tank of fuel at 4 knots than you can at 5.

Stu Jackson · Apr 8, 2009

Fuel consumption

on boats is most usually measured in gallons per hour or hours per gallon, rather than the normal automotive mpg. The reason is that diesels don't usually change their fuel consumption much between 1/2 to 3/4 of their full throttle and boats usually run at 3/4 throttle most efficiently. Cars do change- sitting in city traffic is different than highway mileage, right? Our 21 hp engine uses less than 1/2 gallon per hour. The you do the math: 1/2 gallon per hour at 5 knots = ... speed, time distance...

Of course, backing off from full throttle does save fuel because all you're doing is pushing water around once you try to pass normal hull speed.

A small engine like yours could well do less than our 1/2 gallon per hour.

Sorry, don't have a clue as to your tank's volume, but if you measured its dimensions you could easily figure that one out. If you can't do the math on that, let us know and we'll figure it out for you. We do have some math "wizziz" around here.

sailingdog · Apr 8, 2009

Unless you're trying to drive the boat at hull speed, a small 10 HP diesel should burn about 1/2 gallon of fuel per hour. Figure hull speed is abut 6.24 knots with a LWL of 23', and you can run at 5 knots....with about 1/2 gallon per hour... so figure about 2.5 - 3 gallons of fuel, depending on wind, current, etc, to go 23-26 nm.

Ray T · Apr 8, 2009

According to the Oday site the specs for your boat say you have a 9 gal tank . With the info the rest of the guys have provided you should be able to figure approximately how far you can go on a tank full of fuel. You should have plenty of fuel to get to your destination.

Benny · Apr 8, 2009

It depends which way the current is flowing and which way the wind is blowing. Your engine should burn an average of 1/4 of a gallon per hour. Depending on wind and current you could travel at a speed anywhere from 7 to 3 knots. Anything less than 3 knots you should consider aborting and postponing trip. Chances are you will average around 4.5 NM which will require around 6 hours for your trip or 1.5 gallons. At the extremes you would consume 1 gallon at 7 knots or 2.2 gallons at 3 knots. If you fill the tank you will have plenty of fuel for your trip. The ususal sailboat equiped with a diesel will be matched with a fuel tank and engine combination to provide at least 30 hours of operation. Mind you that not all fuel in tha tank is usable as the engine will start to suck air and quit before the tank is empty. Recommend you calculate your Burn Rate by login the fuel consumed and the number of hours the engine is driven at your regular average engine speed. By finding out the size of the tank and allowing for a reserve of usable fuel you may calculate maximum range in anticipated conditions or allow for reliable calculations on the water as per prevalent conditions.

Roger Long · Apr 9, 2009

You might find this graph for my boat useful to study. The engine is twice the horsepower but fuel consumption varies quite closely with horsepower so you just cut the GPH / HP in half. (The graph is set up based on RPM so you will have to do some figuring.)

Your boat is about 40% of the displacement but smaller and effected by waves more so you could figure half the horsepower to go the same speed length ratio. I cruise at 6.14 knots, a S/L (Knots/Sq. Root of Waterline Length) of 1.21. That would be 5.8 knots in your boat. I need 14 of my 20 hoursepower to do that so you would need 7. .054 gallons per horsepower hour is the fuel consumption for most diesels so you would be burning .38 gallons per hour. You'll want to leave at least 10% in the tank to be sure not to suck air and have a reserve. 9 / .38 = 23.68 so you should have just under 24 hours running time and a range of about 135 miles.

There are a lot of variables on the water so I'm not going to pay your Sea Tow bill if you run out of fuel but this should let you do some planning.

claskey · Apr 9, 2009

I have the engine in my Hunter 27 with a three blade 12X7 prop and over 7000#. I have went 103 miles on 10 gallons at 5.5 knots on lake Huron.

Capn Pete · Apr 9, 2009

Pat,

I used to own a 272LE, and as I recall, it sips about a third of a gallon per hour at cruising RPMs. With a 10-gallon fuel tank (approximately), you should have no trouble whatsoever running 26 miles under power. I know I've done at least that.

Of course, if you want a security blanket, bring along a 5-gal. jerry can of extra fuel. I doubt you'll need it, but it's better to have and not need than the reverse.

(While I have your attention, I hope you'll be thinking about coming to the O'day owners' rOnDAYvous, to be held this year in beautiful Great South Bay. Email me for more details and to be put on the event mailing list.)

Pete
s/v EmmieLou (O-322)
Little Silver, NJ

tweitz · Apr 9, 2009

I used to have an O'Day 272LE and motored far longer than 26 miles with lots of fuel to spare.