Volume of Diesel in reserve.

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oldgit

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My fuel gauge is telling me that it is just about to go on "Reserve"
In order not to conk out somewhere and get towed home by a raggie,would very much like to know how much fuel is now left in my tank.
Using a combination of tape measure and dip stick,we appear have fuel amounting to
423000 cu cms sloshing around bottom of tank..(188 x 75 x 30 cms)
If we divide that by 1000,this should give me 423 litres ???? or around 94 gallons.
Is my maths as rubbish as I suspect,or is this correct,bearing in mind of course that not all this fuel is available for use,due to unknown length of pick up pipes.
 
Can't comment on your maths,given a fair few GT's in the Delhi Golf Club, but your residual fuel would appear to be a bit in the ecxess area , hic...............burb..............cough
 
I usually work out tank size by LxWxH (inchs) then divide by 1728 then X6.22 which gives you capacity in gallons, your reserve using the dimensions you give I made it 92 gallons
 
The boat is a bit of a mongrel beast with a custom built tank.The plate on the top states it holds 1200L.Have just fitted a dipstick, not trusting fuel gauges.
When I hacksaw a nice groove at the bottom of the dip rod just want a rough estimate of how much fuel will be left in tank when it reaches this level.

The dimensions given are not of the tank but the length and width of the tank plus the depth of the diesel showing on my super bodge dipstick.The actual tank is about twice the height of the diesel level.
 
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aquapower said:
Have I misread this, the dimensions given are of fuel what is left when the guage shows reserve? there is no mention of the tank size?
Click to expand...

Yup the measurement of the fuel volume (not tank) is 188L X 75W and 30D (all cms) showing on dipstick when it hits the bottom of tank.
Therefore about 92 or 94 gallons remaining in tank when my gauge needle goes down to reserve.
Normally use around 4GPH so more than sufficent when an hour or two away from home.
 
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you could place a spare canister with diesel on your boat,
and steem until the tank is empty, then you know exactly your range when the gauche is on reserve

quite often we use the tank below reserve level, just to have as less diesel in there as possible, (reduce weight for trailering)
but always with a reserve 20l diesel canister on board
and when we trailer, I put the reserve 20l diesel in the car

I can read my dielsel gauche quite accurate now
 
oldgit said:
423000 cu cms sloshing around bottom of tank..(188 x 75 x 30 cms)
If we divide that by 1000,this should give me 423 litres ???? or around 94 gallons.
Is my maths as rubbish as I suspect,or is this correct,bearing in mind of course that not all this fuel is available for use,due to unknown length of pick up pipes.
Click to expand...
Your math is correct.
Aside from the fact that 423 are actually 93 imperial gallons, in my book. [/pedant]
The key issue is whether the tank size is regular - i.e. 90 degrees constant angle, both vertical and horizontal, between the 3 dimensions you're mentioning. If that isn't the case, knowing how much juice is left can be MUCH more complicated.
 
But if you had electronic fuel injection............................

Sorry, could not resist, just my little joke.
 
Assassin said:
But if you had electronic fuel injection............................

Sorry, could not resist, just my little joke.
Click to expand...

Yea yea yea :)

Will now add fuel in say 50 litre batches and then cut notches in dipstick accordingly.
Perfectly OK with using the electronic fuel gauges but want a fall back method.
Tank is square,so gallons estimate is probably very accurate.So question answered.
Am now going to whip off that nice big easy to access inspection plate on top of tank (which all boats have of course) to see how far pick up pipes go down into fuel.

Thanks to all who contributed.
 
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oldgit said:
Yea yea yea :)

Will now add fuel in say 50 litre batches and then cut notches in dipstick accordingly.
Perfectly OK with using the electronic fuel gauges but want a fall back method.
Tank is square,so gallons estimate is probably very accurate.So question answered.
Am now going to whip off that nice big easy to access inspection plate on top of tank (which all boats have of course) to see how far pick up pipes go down into fuel.

Thanks to all who contributed.
Click to expand...

I ignore my fuel gauge.

I top the tank up making a note of my log.

I know my mpg and calculate the amount of range I have left.

Always done it this way.

Just reset the log as you fill up and when it gets to 200 nm its time to fill up.

If Ive already done 150 nm I wouldnt set off on a 60 nm cruise (unless it was calm).

even if you calibrate your tank by filling in 50L batches I cant see what use your fuel gauge is unless you are going to stop to allow your boat to level before reading.
 
"even if you calibrate your tank by filling in 50L batches I cant see what use your fuel gauge is unless you are going to stop to allow your boat to level before reading"

If the bow of my boat goes up,we are travelling far to fast :)

Only had the boat for a few months and trying to get an idea of the gallons per hour.Hence getting a idea of the reserve,popping in fuel (50l) and then running until fuel drops back to reserve level marked on dipstick.
 
The only way is to run the engine from a five litre drum, at normal usage, when the drum is empty you know what you are burning, don't forget to set your stopwatch, and note tide direction. As for running on "reserve" would not mind betting that half of it is water, and in a bit of a slop it will mix with your diesel and stop you early anyway.
 
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