Fuel Usage...poll

[Mick C]

One of the perenial arguements here in CF is around hybrid propulsion and the majority opinion is that with currently available technology the solution is not yet mainstream viable. Yes, there are people who think differently but I am simply taking a majority view be it right or wrong.

One of the major issues discussed is energy density. One of the missing bits of data for me is the real world energy required. So with this in mind I ask people who are active on their boats...from full time liveaboards to weekend cruisers of catamarans and monos to share with us your diesel or gas/petrol usage. Just a rough annual figure would be wonderful...your normal 12 months, say last your or the year before. We are just looking for some data points to see what datat is out there. Oh yes, its for all engines aboard including gens, etc

To start with I race on a 30 foot mono Thursdays and Saturdays for the spring, summer, fall season. We use about 20 liters for the year. We dump the rest of the tank when we put it into winter storage.

Many thanks in advance...

Mick

[nhschneider]

Having sailed from Southern California to Mexico, through the South Pacific and on to New Zealand in the last 18 months, we've gone through more fuel than we would normally use in a year - probably close to 500 gallons. However, that's between both the propulsion engine and the genset. At cruise RPM, our propulsion engine (a Beta Marine 90) burns about .8 gallons per hour.

When we're just day sailing out of San Diego, we go through about 50 gallons per year.

[Factor]

About 1 Litre per hour per motor and about 100 hours each motor per year.

[Waterway Guide]

About 0.75 gal/hr. when motoring 6kn.

[Mick C]

Originally Posted by Waterway Guide

About 0.75 gal/hr. when motoring 6kn.

So what would you do in a year?

[Waterway Guide]

Originally Posted by Mick C

So what would you do in a year?

Depends on where we're sailing. But the last 2 times that we sailed from the Chesapeake to the SE Bahamas we burned about 300 gal of diesel/yr. (around 400 engine hrs.), but we did a LOT of motoring (ICW).

[Dockhead]

6 - 8 liters an hour for the main propulsion engine, plus genset and Eberspaecher heater. About 100 -- 150 engine hours a year, and maybe 50 hours on the genset. Altogether a couple of tanks a year, sometimes three. About 500 liters per refueling (680 liter tank). So 1000 to 1500 liters a year, which is roughly 250 to 375 gallons.

I have been paying 70 to 90 pence per liter (depending whether I buy it in Guernsey or in Cowes), or $1.10 to $1.50. So I spend up to a couple of grand a year on fuel.

[Hud3]

We averaged about 300 hours per year on our Yanmar 4JH3E, and we seemed to do just a tad better than the published fuel consumption curve. We'd burn 2/3 gallon per hours at 2400 rpm, and do 6.7 knots with a clean prop and bottom in calm conditions. So, about 200 gallons per year for a variety of sailing (coastal and offshore), and charging the batteries at anchor (~45 min/day).
.

[atoll]

over 5 years and 45,000 miles we used 40,000 liters running our 63 ft expediton yacht.
150 hp volvo(6-12 l/ph) 4500 hrs+8kw genset(2 l/ph) 5000 hrs.
of which aprox 18000 miles was motoring into 25kt headwinds(3x red sea,4x med)

[djmarchand]

Mike C:

As you can probably tell by now, you are going to get a variation in gph numbers depending on speed, size and weight of the boat and a huge variation in number of hours used each year depending on whether it is in and out of a slip or long range cruising. I filled my 50 gallon tank less than once one year, but I purchased 500 gallons the next.

I don't see any point in answering unless that is what you wanted to know- how wide a variation exists.

Here are some baseline numbers: a 40', 20,000 lb cruising sailboat uses about 15 hp to cruise at 6.5 kts. Most diesels produce 18 hp for each gph burned. So that cruisng boat will burn 15/18 = .88 gph. That is just one point on a very, very wide curve.

Hybrid drive systems make a lot of sense for commuter, short trip automobiles. You replace the big, inefficient engine which is only used occaisonally for rheavy acceleration for maybe ten seconds with a much smaller engine, plus a battery and electric motor for acceleration. And as a bonus you get "free" energy from regenerative braking.

A displacement speed cruiser uses its horsepower at a constant rate (usually) and when it needs a lot more- to battle a head sea for example, it usually needs it for more than a minute, more like hours. That 40', 20,000 lb boat needs at least a 40 hp engine in these conditions. So you can cut the engine size in half or less for routine usage, but the electric energy storage gets to be enormous to cover the peaks. And unlike a gasoline engine a modern diesel is pretty efficient at 1/3-1/2 load where most cruisers operate their diesel.

And diesel fuel plus the weight of its tank produces 10-20 times the work per pound than a battery driving an electric motor does

Diesels are a pretty good choice for a cruising boat. There isn'tnow nor will there likely ever be anything better.

David

[Cotemar]

Volvo Penta D1-30hp
In 2011 I used the motors 67 hours per engine.
Running at 2200 using .6 gal per hour at 8.5 knots only running one engine at a time.

67 hours x 2 engines = 134 total hour in year 2011

English
134 hours time .6 gal. per hour = 80 gal. used for year 2011

Metric
134 hours time 2.271 liters per hour = 302.83 liters used for year 2011

[Mick C]

Originally Posted by djmarchand

Mike C:

As you can probably tell by now, you are going to get a variation in gph numbers depending on speed, size and weight of the boat and a huge variation in number of hours used each year depending on whether it is in and out of a slip or long range cruising. I filled my 50 gallon tank less than once one year, but I purchased 500 gallons the next.

I don't see any point in answering unless that is what you wanted to know- how wide a variation exists.

Here are some baseline numbers: a 40', 20,000 lb cruising sailboat uses about 15 hp to cruise at 6.5 kts. Most diesels produce 18 hp for each gph burned. So that cruisng boat will burn 15/18 = .88 gph. That is just one point on a very, very wide curve.

Hybrid drive systems make a lot of sense for commuter, short trip automobiles. You replace the big, inefficient engine which is only used occaisonally for rheavy acceleration for maybe ten seconds with a much smaller engine, plus a battery and electric motor for acceleration. And as a bonus you get "free" energy from regenerative braking.

A displacement speed cruiser uses its horsepower at a constant rate (usually) and when it needs a lot more- to battle a head sea for example, it usually needs it for more than a minute, more like hours. That 40', 20,000 lb boat needs at least a 40 hp engine in these conditions. So you can cut the engine size in half or less for routine usage, but the electric energy storage gets to be enormous to cover the peaks. And unlike a gasoline engine a modern diesel is pretty efficient at 1/3-1/2 load where most cruisers operate their diesel.

And diesel fuel plus the weight of its tank produces 10-20 times the work per pound than a battery driving an electric motor does

Diesels are a pretty good choice for a cruising boat. There isn'tnow nor will there likely ever be anything better.

David

Yes, the numbers and the spread are very interesting and useful. It really is interesting that patterns are emerging regarding usage, heavy, light etc and a nice correlation to fuel. So yes, these are interesting. Thanks to everyone that has contributed...keep em coming!

[rcmpegasus]

I cruise 5-6 months a year, live aboard a couple months a year. While a sailboat, I motor about 30 percent of the time as winds tend to be very light here. The last two years I used abut 400 gallons each year, my engine burns 2 gallons an hour at cruise. No generator at this time.