How Much Diesel Use

[Andrewcook]

How much  Diesel Fuel does the Heater uses when you have it on for a time. Now the weather has changed as  it's warming up once again thank goodness.

[grendel]

depends upon the rating of the heater,but it can be up to a litre per hour I would imagine, the one I had on my VW variant (very first car) I believe used a pint of petrol per hour.

[annv]

Hi Andrew If you look in back of the user hand book it will tell you the hourly consumption. John

[BrundallNavy]

You could always put on an extra jumper if your worried about the fuel, personally I would rather be warm and comfortable regardless of cost. 

[BroadAmbition]

personally I would rather be warm and comfortable regardless of cost. 

Ditto

Griff

[Vaughan]

I have estimated it at around 2 litres an hour or maybe a bit more.  It is hard to estimate as it comes from the same tank as the engine, but the difference in a hire boat's average consumption, between summer and late autumn, gives you a fair idea.

[NeilB]

Just had a quick look at the tech spec for an Eberspacher D5 and the max is 0.66 l/ph and 85W at full power, The Webasto is probably similar.

[Vaughan]

10 minutes ago, NeilB said:

the tech spec for an Eberspacher D5 and the max is 0.66 l/ph

I had a feeling someone would say that!  Personally I think that, like so many of these sort of statistics, the actual consumption might be more than the manufacturer's quoted figures!

My feeling is based on running hire boats with hour meters, where the hours cruised against the diesel used, give a very accurate idea of consumption.  All I know is that a cruise of the same number of hours on the same boat, shows a very large increase in consumption in the colder months of the season.

[floydraser]

No experience of Eberspachers in boats but I have in lorries, and they are controlled by thermostats. Assuming the same for boats then a lot depends on how one likes to set the temperature. At home, some people like to whack the temperature up and walk around in tee shirts all day. We know this from the arguments in the office over where to set the aircon temp!

Consumption then is surely relevant to the one's preferred temperature setting?

[Meantime]

My Mikuni heater is rated at 5kW and uses between 0.19 - 0.60 l/h. That's the official stats but what does it mean in practice? Well as the diesel all comes from the same tank and there is no hour counter on the heater it's hard to say definitively. What I can say is that in the Summer I get about 2.6 - 2.7 miles to the litre and n the Winter this drop to about 1.9 - 2.1 miles to the litre. The difference being the fuel used by the heater.

[NeilB]

46 minutes ago, Vaughan said:

I had a feeling someone would say that!  Personally I think that, like so many of these sort of statistics, the actual consumption might be more than the manufacturer's quoted figures!

Happy to oblige 

I cannot speak for Eberspacher but on our products the max fuel consumption is pretty accurate and has been checked against flow meters and on our diagnostic tool.

We're onboard Lightning for a few days over Christmas but to be honest I don't take much notice of the fuel consumption.  I'm sure my wife will let me know if I need to turn the heater up!

[Meantime]

I must confess the best way I've found of improving the heater fuel economy is to stay in the pub longer. I've even found that the closer you sit to an open fire in a pub, the longer you stay and therefore the less diesel you burn on heating.

I've tried to demonstrate it with the following formula

distance from fire * outside temp = resistance to leave pub.

number of pints / hours spent in pub = hourly pint rate

price of a pint * hourly pint rate - cost of running boat heater = £s per hour

£s per hour * resistance to leave pub = a figure which if high means its time to return to the boat, if low its time to get a round in. 

 

[vanessan]

2 minutes ago, Meantime said:

I must confess the best way I've found of improving the heater fuel economy is to stay in the pub longer. I've even found that the closer you sit to an open fire in a pub, the longer you stay and therefore the less diesel you burn on heating.

I've tried to demonstrate it with the following formula

distance from fire * outside temp = resistance to leave pub.

number of pints / hours spent in pub = hourly pint rate

price of a pint * hourly pint rate - cost of running boat heater = £s per hour

£s per hour * resistance to leave pub = a figure which if high means its time to return to the boat, if low its time to get a round in. 

 

Meanwhile the boat gets colder and colder………….brrrr!

[Smoggy]

34 minutes ago, vanessan said:

Meanwhile the boat gets colder and colder………….brrrr!

Nah, I phone the heating from the pub as I get the last* round in and it runs for an hour with extra ducts running under the duvet, when we get back the boat is toasty and the bed is roasted, get in a warm bed and you stay that way all night without heating on.

As for the open fire/pub theory, we've been known to take a bag of logs along with us in winter.

* last may not really mean last.

[Bikertov]

1 hour ago, Meantime said:

I must confess the best way I've found of improving the heater fuel economy is to stay in the pub longer. I've even found that the closer you sit to an open fire in a pub, the longer you stay and therefore the less diesel you burn on heating.

I've tried to demonstrate it with the following formula

distance from fire * outside temp = resistance to leave pub.

number of pints / hours spent in pub = hourly pint rate

price of a pint * hourly pint rate - cost of running boat heater = £s per hour

£s per hour * resistance to leave pub = a figure which if high means its time to return to the boat, if low its time to get a round in. 

 

My maths is a bit rusty these days, but I think there is an error in your second formula ... surely it should divide, not multiply ?

Otherwise the resistance to leave increases when the outside temperature increases, whereas the resistance to leave should decrease when it gets warmer ?

So I think the correct formula should be:

distance from fire / outside temp = resistance to leave pub.

[Meantime]

43 minutes ago, Smoggy said:

Nah, I phone the heating from the pub as I get the last* round in and it runs for an hour with extra ducts running under the duvet, when we get back the boat is toasty and the bed is roasted, get in a warm bed and you stay that way all night without heating on.

As for the open fire/pub theory, we've been known to take a bag of logs along with us in winter.

* last may not really mean last.

I don't have the ability to phone my heater, but do have a timer on the thermostat, so normally set it to come on at 20:30 for a couple of hours to warm the boat up before we return to the boat. However I must confess there have been occasions when that plan doesn't work too well, like when you return after last orders or after a lock in to find the heater turned off an hour or two ago.

[Meantime]

4 minutes ago, Bikertov said:

My maths is a bit rusty these days, but I think there is an error in your second formula ... surely it should divide, not multiply ?

Otherwise the resistance to leave increases when the outside temperature increases, whereas the resistance to leave should decrease when it gets warmer ?

So I think the correct formula should be:

distance from fire / outside temp = resistance to leave pub.

I must confess I just made it up on the spur of the moment, it could do with some refining. I'll look into improving when next sheltering in the pub from a cold boat. 

[Bikertov]

5 minutes ago, Meantime said:

I must confess I just made it up on the spur of the moment, it could do with some refining. I'll look into improving when next sheltering in the pub from a cold boat. 

In which case you might want to add to following expression at the end of your formula:

Decision to leave the pub = 'True' if (Resistance to leave the pub < number of pints stored aboard the boat)

 

Just saying ...

[Smoggy]

After an hour I just call it again, be scuppered when 2g gets switched off though.

Call no.2 usually indicates kraken o'clock... Or black magic if I have some. Mmmm rummmmmm.

[Cal]

The 2kw Webasto air blown diesel heater we had on our boat used a maximum of 0.25 litres per hour. In practice it was less then this as the thermostat kicked in and out.

 

A 4kw Webasto air blown diesel heater uses at most 0.5 litres per hour.

 

We never bothered about how much it used. We preferred to be warm and dry.

[Cal]

7 hours ago, Smoggy said:

Nah, I phone the heating from the pub as I get the last* round in and it runs for an hour with extra ducts running under the duvet, when we get back the boat is toasty and the bed is roasted, get in a warm bed and you stay that way all night without heating on.

As for the open fire/pub theory, we've been known to take a bag of logs along with us in winter.

* last may not really mean last.

We never had that on the boat but having got it on the motorhome now we wished we had fitted it. It is so useful.

[LizG]

Is this a stupid question but don't hire boats have dip sticks these days. Check what's in before and after use?

[Smoggy]

1 hour ago, LizG said:

Is this a stupid question but don't hire boats have dip sticks these days. 

They always did, just behind the helm.

[vanessan]

1 hour ago, LizG said:

Is this a stupid question but don't hire boats have dip sticks these days. Check what's in before and after use?

We were told a while ago that the use of dipsticks is frowned upon these days. I’m sure there will be someone who can verify that. 

[Meantime]

15 minutes ago, vanessan said:

We were told a while ago that the use of dipsticks is frowned upon these days. I’m sure there will be someone who can verify that. 

I'm not so sure about that, our toll money seems to pay for a fair few at Yare House