VP 2003 fuel consumption

Sans Bateau

Sans Bateau

Well-Known Member
Joined
19 Jan 2004
Messages
18,956
Visit site
After motoring both ways across the channel last weekend I thought I'd fill the tank and work out the litres per hour.

2.40 litres per hour at 2000 rpm, is that about right?
 
Reckon that's about right. I tend to motor my 2003T at around 2500-2700rpm, at which speed it uses about 4 litres an hour.
 
I too have wondered the fuel consumption of my VP 2003.

A google search found an advert on boatshed.com (ref 36654) of a boat similar to mine where the seller claims the consumption at 5kn cruising speed is approx 1.4 l/hr. 5kn in smooth water and no wind requires 2000 rpm on my boat.
 
Blimey ........ my overpowered boat with 42HP 4-107 ..... 30 ltrs in 18 hrs ......... making 4.5 - 4.8 kts motor sailing in very light to zero winds ...

Seems a bit like the old 1.6 vs 2.0 litre argument of old Ford cars ... People bought the 1.6's thinking they were more economical ... in fact the 2.0 ltr often beat it by not working quite so hard ... having done this - I know it works ...

Even at half throttle - I'm still at 3 ltr/hr .... only when I start to get crazy ... my boat can hit 9kts under engine ... witnessed ! Then its probably using 5 ltr/hr ... plus plenty black smoke and crud.

Interesting that many boat adverts quote .... 1/2 gall/hr ... regardless of engine / boat ..... 1/2 gall sounds small ... but in fact is 2.3 ltrs.

I have complied a fuel chart boats against engines .... and just because a boat has a big engine doesn't mean it burns more ... (we are talking raggies here - MOBO's are a different ball-game completely ....).
 
One horsepower-hour uses about 0.15 litres. So at your rate of fuel consumption, your engine would have been delivering an average of 16 hp into the prop. Does that sound about right? If so, then theory agrees with observed fact = /forums/images/graemlins/smile.gif
 
[ QUOTE ]
Even at half throttle - I'm still at 3 ltr/hr

[/ QUOTE ]What do you mean by "at half throttle"?
 
In my Moody 31 With the 2003 engine I motor at about 2000 revs which gives me circa 5 knots.On a recent trip to Holland my consumption was about around 1.7lt per hour.My engine was rebuilt in 2000 with new pistons,bearings,pumps etc.
 
So it sounds as though you are taking 50% power at 2000 RPM. I don't know the engine's torque speed curve or what that means in terms of the prop. Given that you now know fairly accurately the POWER and SPEED at 2000 RPM you have one point on the curve for your boat, which is a lot more than most folks have. Ideally you'd run another trial at, say, 2300 RPM but of course if you are in any sort of sea the figures become unreliable as consumption can rocket.
 
It was a good opportunity to run the test as a benchmark last weekend as the sea was pretty flat both journeys. Plus a constant engine speed for a long time.

I would like to do the test again at varying engine revs to see what effect it has on the consumption/speed. I know if I crank up to 2700 rpm the boat will be doing more like 7.5 knts, but alas the fuel will disappear quicker I suspect.

With so much data out there, you would have thought someone would have a spreadsheet with hull length/boat speed/prop type/etc as parameters, the stats being fuel used. Ah! I can only hope.
 
exactly that ........ 1/2 throttle ... I don't have a rev counter - it's a job that has been on the list for about 5 years now !
 
When I made up my sheet - I kept it simple -boat size, engine HP and consumption. Too many variables out there to get more scientific.

Most people who have asked me for the sheet - I think have found it a good average guide.

My engine as quoted above proved more economical than expected - but I still will work on average 3 ltr/hr consumption for planning. If I use less - it's a bonus.
 
[ QUOTE ]
exactly that ........ 1/2 throttle ... I don't have a rev counter - it's a job that has been on the list for about 5 years now !

[/ QUOTE ]Ah! It doesn't mean very much, then, since the 'throttle' is connected to a governor which controls engine speed not power and is in any case not necessarily linear.
 
If you look on the data sheet for the Volvo 2003 engine, it appears that peak efficiency (max torque, lowest fuel consumption) is at 2300 rpm.
 
You must log in or register to reply here.

Share this page

Top