Expected consumption rates MD2040

[shortjohnsilver]

Fuel gauge is kaput. However I’ll be crossing the Thames estuary Harwich to Ramsgate before I can get it fixed. Fuel tank is black plastic - French boat and impossible to dip. I’ve twenty litres in Jerry cans and I believe that the tank is about half full. Just for piece of mind I thought I would ask the assembled here nether anyone could provide some sort of fuel consumption rates for a VP MD2040. This is should the wind drop out completely when negotiating the sandbanks and associated tides.
I have been told 2 l/h at about 2000 RPM which would be fine but being as I’m a pessimist I think that could be more 3 l/h

I generally cruise at 2200 RPM and this is smooth giving 6knots ignoring tide/weather

Anyone have this engine in their 36/37 footer and maybe give a ball park figure?

 

[john_morris_uk]

Fuel gauge is kaput. However I’ll be crossing the Thames estuary Harwich to Ramsgate before I can get it fixed. Fuel tank is black plastic - French boat and impossible to dip. I’ve twenty litres in Jerry cans and I believe that the tank is about half full. Just for piece of mind I thought I would ask the assembled here nether anyone could provide some sort of fuel consumption rates for a VP MD2040. This is should the wind drop out completely when negotiating the sandbanks and associated tides.
I have been told 2 l/h at about 2000 RPM which would be fine but being as I’m a pessimist I think that could be more 3 l/h

I generally cruise at 2200 RPM and this is smooth giving 6knots ignoring tide/weather

Anyone have this engine in their 36/37 footer and maybe give a ball park figure?

That’s not an easy question to give an accurate answer to. It depends on so many factors.

We had a VP2040 in our 39’ Westerly Sealord and IIRC we used about a litre/mile at 2200 rpm.

Lower rpm dramatically helps fuel consumption.

How big is your main tank?

If you can rig a clear length of flexible tube to the fuel tank, holding it up against the tank will show you the level of fuel in it. You could do this as a temporary measure (if you’ll pardon the pun!!)

 

[NBs]

Hi,

You can look this.

Best cruise RPM on VolvoPenta MD2040 for fuel economy - Cruisers & Sailing Forums

Nbs

 

[B27]

Consumption varies hugely with speed, flatness of water, headwinds/tailwinds and particularly how clean the bottom is.

Bashing into a headwind and chop can use literally 5x the fuel of the same speed in flat water on a calm day, so knowing some 'average' is somewhere between useless and potentially dangerous.
I'd rather just take plenty in cans and know I can't possibly run out.
Maybe put 10 litres in before any critical bit like a harbour entrance.

I get that it might be nice to not have much in the tank when replacing the gauge sender if needed.

 

[lustyd]

My SO36.2 with MD2040 did about 2l/hour last week at 1700rpm crossing the channel with brand new antifoul in good conditions (no wind whatsoever!). Previously done 4-5l/hour with dirty bottom at 2100rpm so results certainly do vary.

If the sender is working you could measure resistance directly as the values are known for full and empty and the change is linear.

 

[Beneteau381]

Fuel gauge is kaput. However I’ll be crossing the Thames estuary Harwich to Ramsgate before I can get it fixed. Fuel tank is black plastic - French boat and impossible to dip. I’ve twenty litres in Jerry cans and I believe that the tank is about half full. Just for piece of mind I thought I would ask the assembled here nether anyone could provide some sort of fuel consumption rates for a VP MD2040. This is should the wind drop out completely when negotiating the sandbanks and associated tides.
I have been told 2 l/h at about 2000 RPM which would be fine but being as I’m a pessimist I think that could be more 3 l/h

I generally cruise at 2200 RPM and this is smooth giving 6knots ignoring tide/weather

Anyone have this engine in their 36/37 footer and maybe give a ball park figure?

My Beneteau 381 has an MD 22, a two litre Diesel engine based on an old Perkins Prima. It does 1.8ltrs an hour, these figures are the average from our trip to Portugal over a month. I would expect yours to do similar.

 

[Tranona]

+/- 2l hour is a good basis in normal conditions. Sound like you have well over 70l in your tank and back up so 35 hours. More than enough for your passage (and back agoin!)

 

[shortjohnsilver]

Thanks all. I’m really not certain how much I’ve got in the tank currently, we had a 11 hour hard slog against weather and tide a week or so ago - don’t ask and a further 8 hrs coming over to Harwich but easy low wind motor sailing. At 4 -5 ltrs per hour I’m concerned we’re getting a bit low. I could pop the 20 ltrs in and all may very well be fine but….. I’m going to fill up full and then I know the tanks full 130ltrs and keep the 20 ltrs in reserve but, fingers crossed, the rather will be great the wind good. Tides will be with us mostly.
Read the thread NB’s thanks that was helpful. Also Lustyd was reassuring. Beneteau381 that’s a good marker too and concurred by Tranona. Again thanks all appreciated. Happy now.

 

[LittleSister]

Which particular engine you have has very little influence on the fuel you use. The boat, the speed, and the conditions are the far more influential factors.

The engine will only deliver the power needed to maintain the engine speed you have set (which is determined by the second set of factors above), and only consume the amount of diesel needed to produce that amount of power. The fuel consumed to generate a given amount of power varies very little between different engines compared to the other factors.

 

[Beneteau381]

Which particular engine you have has very little influence on the fuel you use. The boat, the speed, and the conditions are the far more influential factors.

The engine will only deliver the power needed to maintain the engine speed you have set (which is determined by the second set of factors above), and only consume the amount of diesel needed to produce that amount of power. The fuel consumed to generate a given amount of power varies very little between different engines compared to the other factors.

Depends on the heavy hand as well, running with the governor on max, dictated by the heavy hand is a factor. My consumption on the trip was averaged out over varying conditions and is a good average figure for MY boat. Running against a short wavelength will increase consumption as the engine governor tries to keep the revolutions set as it climbs the swells.

 

[LittleSister]

Depends on the heavy hand as well, running with the governor on max, dictated by the heavy hand is a factor. My consumption on the trip was averaged out over varying conditions and is a good average figure for MY boat. Running against a short wavelength will increase consumption as the engine governor tries to keep the revolutions set as it climbs the swells.

Yes, as I said, consumption will depend heavily on such factors.