Fuel consumption when to fill er up?

Uricanejack

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Read a new sailors questions about charts which drifted into fuel. had nothing sensible to add about charts so started a fresh thread on fuel consumption.

As a former motor bike rider, I never had a guage just filled her up ran it till it stopped switched to reserve and went on again and stopped for petrol at the next station.
Had an MG midget with a duff gauge, kept a little can in the boot. used to run out from time to time on the Clyde Express Way in the morning rush, by the time I'd put my reserve in the tank there would be quite a jam behind me. but the way ahead was quite clear:)

Always dipped my tanks with a stick before flying, figured out air speed ground speed altitude ect and flight time and reserve. Never ran out but used a bit of reserve. makes you keen to land.

I do worry about running out.

Bleeding the fuel lines all the way to the injectors. a good thing to learn, but best avoided. I tend to fuel up at the next opportunity after my fuel gauge goes bellow half. I have significant doubt about my fuel gauges accuracy. haven't really figured out a stick option. I suppose a bendy cane would work. A sight glass would be better. I tap the tank sort of works.

I have run out of fuel once on a sailboat, not a big problem I just sailed it to the fuel dock. getting the dam thing to run again was a problem.

Motor boating or motor sailing with motor being your primary I would suggest keeping a minimum 25 percent as a reserve. also a rough idea of your hourly fuel consumption coupled with cruising speed, will give you an idea of how far you can go ,

I don't use a lot, this year I have used 35 liter's so far. but I was getting worried so I topped er up the other day.

Just wondering what other folks do and what you would advise a new sailor.
 

RichardS

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I have 2 x 200L tanks and keep 2 x 20L jerry cans full for each tank which gives me a useful 20% reserve.

After this year's cruise I just tipped in the jerry cans which more or less refilled the tanks and then refilled the jerry cans just to make sure that the fuel in the cans is not getting too old. I have fuel gauges which are not very accurate but give me an idea about what's happening.

Richard
 

prv

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My tank's rectangular, so the gauge ought to be linear. I suppose I haven't tested that but I have no reason to doubt it. There is still a dipstick on board from before I fitted the new gauge, but you have to unscrew the sender to use it.

I like to start any significant passage (eg cross Channel) with a full tank, even if I expect to sail. For local cruising I'm rather more casual, and just top up when I notice it getting a bit low. In the Solent we're never far from a fuel berth.

If we were to run out, there's a ten-litre can in the locker. Bleeding the engine holds no fears - the hand pump at the tank will push fresh fuel right through the system to the injector pump, air coming back through the return line. I believe the injector lines are self-bleeding, but if not I have no problem cracking the nuts on the ends.

Pete
 

PhillM

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See through 20l tank, marked at quarters. Easy to see my opening the locker and mk1 eyeball.

Spare 10l can that really only holds 8l. Always fill up the tank from the can and the can on the fuel dock.
 

johnalison

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I carry 140 litres in a rectangular tank and do about two litres to the hour. The gauge is consistent but non-linear, but fortunately is pessimistic, so there is more left in the tank than suggested. I try not to get near the empty stage, partly because I don't carry spare fuel, and partly because I don't want air to be sucked in if the diesel slops around in rough water. I can bleed the system, but I don't fancy having to do it while on the move, especially if in a hurry.

A week ago we left Blankenberg for home after motoring most of the way via Amsterdam from the Lauersmeer. The gauge showed something less than half and refilling was inconvenient. My calculation was that we had at worst sixty litres left for thirteen hours motoring, needing, say, twenty five litres, so that I should have at least thirty five litres left. In the event, I could only get ninety litres in back home, so I must have ended with fifty litres remaining and needn't have caused myself to worry.
 

Uricanejack

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My tank is reputed to be 20 gal. Trouble is being built in Canada for sale in the US. The documents don't mention if its imperial or US gallons. I did find a reference to 76 liters which indicates US. I use 1 gallon or 4 liters per hour as rough estimate for consumption which appears to be very conservative. I have never used that much. Which if I keep a reserve of 25% gives me just under 60 liters or 57 or about 15 hours I tend to head for the fuel dock if i have over 10 hours approximately.
I should keep a better fuel and hours record. I do record when I fuel up. My actual engine use may not be very accurate.
 
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Uricanejack

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See through 20l tank, marked at quarters. Easy to see my opening the locker and mk1 eyeball.

Spare 10l can that really only holds 8l. Always fill up the tank from the can and the can on the fuel dock.

My old boat had a 25 liter plastic tank you could see through. and I kept a spare can of about 5 liter. Its was a smaller boat with an outboard. If I ran it dry it was a simple matter just to pour my reserve in. I use a similar system with my small mobo. Its a fishing machine. I have two 25 liter tanks, Head out, get to where I am fishing, troll or mooch from same tank, When it runs dry I have a full tank to get home. Also I can carry it to any gas station.

I now have a diesel with a metal tank. non see through. Up to now I don't carry any spare diesel.
 
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duncan99210

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I don't know if I'm unusual but I keep a log of engine hours run. We burn about 2 litres an hour when on the move and about 1.4 litres when static, so it's easy to keep track of consumption. The tank holds a nominal 150 litres and I aim to refuel when I estimate I've used 100 litres. Usually reasonably accurate at estimating how much is needed. This level of detail was forced on me by the fuel gauge opting out for a time and I've never broken the habit. All that said, just at the moment in Grece I'm topping off the tank on a weekly basis, just in case it all goes pear shaped......
 

Caladh

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I don't know if I'm unusual but I keep a log of engine hours run. We burn about 2 litres an hour when on the move and about 1.4 litres when static, so it's easy to keep track of consumption. The tank holds a nominal 150 litres and I aim to refuel when I estimate I've used 100 litres. Usually reasonably accurate at estimating how much is needed. This level of detail was forced on me by the fuel gauge opting out for a time and I've never broken the habit. All that said, just at the moment in Grece I'm topping off the tank on a weekly basis, just in case it all goes pear shaped......

I wouldn't like to count on a fuel gauge giving accurate info! Our engine does 1.5L an hout and can go 2.5 days on a full tank at "normal" motoring. Like Duncan an engine hours metre and log of hours is what we use to ascertain fuel usage - hasn't let us down yet. We also carry an extra 20 - 40L of fuel in cans.
 
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GHA

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A handy hint I picked up on deliveries is to log engine hours from when you last filled up, so at a glance you know how many hours the engine has been running since the tank was full.

Or does everyone do that anyway? :)
 

johnalison

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That's fine until your Volvo display packs up, which it always will, and then it's pen and paper, which is too tedious for me. I do it the other way round; I wait until I fill up and record half of that as my engine hours.
 

Sandy

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I have a 40L tank and use about 30L a year. The motor is used for pottering around the mooring and getting out to sea. I start the season with a full tank and a full 10L can on-board. At the end of each trip I top up the tank from the can and when the can is empty I bring it ashore to fill up; I use white diesel as it is not worth the faff getting red. If we have been away on a long trip or had to motor then I fill the tank up over the next few visits to the boat. I always, always check the tank at the start of each trip with my trusty dipstick. :encouragement::encouragement:
 

Champagne Murphy

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As said by Duncan, monitor engine hours. Got a little timer I fitted and I work on 2l/hr as a worst case scenario. Only time I didn't check we ran out in Margate Roads. Luckily we had a good breeze and 20l (of white, it MUST be white if it's in a jerry can) in the locker for just such stupidity. Had to mop up the spillage after but hey......
 

pathfinderstu

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I have an electric fuel gauge on Beneteau I bought recently and found it useless. so fitted an cheap Chinese Engine hour clock as the one on the yanmar instrument panel had packed up, when the clock gets to about 25 hours I fill up with about 70 litres to fill the 200 ltr tank.
I ike to try and keep it on the full side especially in winter as have heard about condensation problems inside a tank on the part where there is no fuel
 

snooks

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I have a sight tube, but years of red diesel has coloured it the same as diesel. I keep thinking of something small bore that will fit in the tube and not go into the take, but I remember this after I fill up. Latest thought was a bit of thin wooden pencil in the tube, rather than a plastic bead.

But I always carry 20l spare (10 hours motoring) and keep an eye on the engine hours.

I ran out on the first trip of the season (knew I was low and checked I had spare fuel), it's a 5 minute job to set the syphon pump refilling, find the tools and bleed the engine.

I keep meaning to find a bit of wood I can dip the tank with...actually you know what, I'm going to go to homebase now and get a bit of doweling.
 

Daydream believer

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I have 2 x 200L tanks and keep 2 x 20L jerry cans full for each tank which gives me a useful 20% reserve.

After this year's cruise I just tipped in the jerry cans which more or less refilled the tanks and then refilled the jerry cans just to make sure that the fuel in the cans is not getting too old. I have fuel gauges which are not very accurate but give me an idea about what's happening.

Richard

When you do your dayskipper see if the instructor could give you a quick maths primer at the same time:ambivalence:
 
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