MD2030 Volvo - fuel consumption

[MM5AHO]

Have noted a reducing fuel consumption and am puzzled by this.

In the past had worked on a good approximation of 2 - 2.5 miles per litre ( good mixed imperial and metric here).

But this summer the engine has used far less, and apparently improving each trip.

Last was about 24 hours running and used 11.9 litres. Thats about half a litre an hour.

Typical cruising speed under power is 5-6kn.

Any ideas what might have caused this change?

 

[Tranona]

Have noted a reducing fuel consumption and am puzzled by this.

In the past had worked on a good approximation of 2 - 2.5 miles per litre ( good mixed imperial and metric here).

But this summer the engine has used far less, and apparently improving each trip.

Last was about 24 hours running and used 11.9 litres. Thats about half a litre an hour.

Typical cruising speed under power is 5-6kn.

Any ideas what might have caused this change?

Probably more to do with the way you are measuring your fuel usage. Consumption is a function of hours run and power used - the latter almost directly correlated to revs. So if your engine is powering the boat at 5-6knots and is properly propped you are using 2000-2500 revs. You are using at least 1.5 litres an hour. Just look at the specific fuel consumption curves for your engine. If you are using only .5 litre an hour you are only using 4 hp (approx) which I guess is about 1000 rpm.

Can't remember the exact power outputs, but 2000 will be around 12 hp (1.5 litre an hour) and 2500 18 hp - 2.25 litres an hour.

So check your 11.9 litres - should be at least 30 litres unless you have found the magic formula to reduce consumption of diesel engines by two thirds!

 

[TonyS]

My 2030 has used an average of 1.98 l/hr over the last 5 years. Cruising speed 6 kts and 2200 rpm. If that is any help. I just record engine hours for a full tank.

 

[MM5AHO]

Fuel consumption was measured by filling the tank to the top, and relying on the bowser display. Thats Dunstaffnage Marina.
Could be of course that the bowser is wrong? In that case, queue up there for good value diesel.
But the dip stick that has worked well for nearly 30 years agrees with the bowser.

5-6 kn probably about 2000-2500 rpm (rpm meter stopped working).

Mystery!

 

[Tranona]

Well, I am sorry it is just not possible to run a diesel producing somewhere around 15hp for 24 hours on 12 litres of fuel. If you could, all our global warming problems would be over and you would be rich!

I have a 2030 and criuse at 2400 revs and in line with TonyS consume around 2 litres an hour. It is actually irrelevant which engine you have, the specific fuel consumption (that is the amount of fuel consumed to produce x HP or KW) is very little different.

The only differences in actual use is the efficiency of the propeller and the characteristics of the individual boat that can have a marginal effect on consumption.

I don't have an explanation - but are you sure the pump was set at litres and not gallons?

Whatever it was, suggest you plan your cruising range based on the realistic 2 litres an hour!

 

[scottie]

fuel

old rule of thumb for fuel useage gallon diesel = 20hp/hour so say 2ltr is 10hp/hr new money

 

[achwilan]

Fuel consumption was measured by filling the tank to the top, and relying on the bowser display. Thats Dunstaffnage Marina.
Could be of course that the bowser is wrong? In that case, queue up there for good value diesel.
But the dip stick that has worked well for nearly 30 years agrees with the bowser.

5-6 kn probably about 2000-2500 rpm (rpm meter stopped working).

Mystery!

ahem... no mystery, just pure miracle !...
you should take advice from a bishop ...;-)

 

[puddock]

Fuel consumption was measured by filling the tank to the top, and relying on the bowser display. Thats Dunstaffnage Marina.
Could be of course that the bowser is wrong? In that case, queue up there for good value diesel.
But the dip stick that has worked well for nearly 30 years agrees with the bowser.

5-6 kn probably about 2000-2500 rpm (rpm meter stopped working).

Mystery!

Maybe it is the Dunstaffnage diesel........ I went to fill up, got 5 litres in and tank started overflowing !!!
Or maybe I should keep a better record of my engine hours. (My boat has clear plastic hose as a sight glass - that has gone dark brown and opaque over time. Another job this winter !)

 

[[10753]]

Interesting thread. I too have Volvo 2030. Typically it seems to burn about 1 litre per hour at 2000 rpm (5kts). Increase of revs to 2500 increases consumption to 1.5 litres per hour (5.5 kts).

 

[Skylark]

I, too have a beloved Volvo MD2030. My 2009 season fuel consumption is significantly better than any of the last 4 years. It had been consuming 2.0 to 2.5 l per hour but this season its closer to 1.5 l/hr.

Being a bit of an anorak I read through my logbook. This season, motoring has been mostly motorsailing or motoring in fairly calm seas. Previous years have experienced more hard-work slogs to windward in angry seas.

When I last topped-up the tank, I was almost pleased to pay the bill.......I was expecting to make a larger contribution to President Brown's Incompetence Bail-out Fund.

Oops, sorry, couldn't help myself!