Petter Mini Twin Fuel Consumrtion

kolster

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Can anyone please give me a figure for the fuel consumption of a Petter AC2WM Mini Twin engine? I can't find it anywhere except in a manual where it states that the engine flat out gives 12HP or 8.95 kW at 3600 rpm and uses 280g/kWh, I presume they mean grams not gallons as the latter would be more in line with the QE2, I've worked this out using diesel with a SG of 0.85 grams/cc as approx' 3L/hr, is my maths correct?
Thanks
John
 
Length of string method gives c.1l/hr per 10hp so your (more considered) calc. seems high. WOT figure would be thirsty but not that thirsty?
Above method tallies well with my previous and current Yanmars 8hp (YSM) then 15hp (2QM)
 
fuel consumption on diesel engines is much the same irrespective of make as thermal efficiency does not vary much. It is in direct proportion to power demanded. You will probably draw around 8-9hp when cruising. The rule of thumb quoted above of 1l per rated hp is pretty accurate. So expect just around a litre an hour or a bit over. Keep a fuel log against hours run for, say 50 hours and you will get an accurate figure for your type of usage. Start with a full tank and note hours when you refill to the top.
 
Surely it's easier to top up, run for a couple of hours and add fuel!? You'll get an accurate figure the more you run it before you add fuel! It's not going to be very much either way, but it will vary quite a bit depending on the throttle opening used, probably doubling if you're nailing it...
 
Surely it's easier to top up, run for a couple of hours and add fuel!? You'll get an accurate figure the more you run it before you add fuel! It's not going to be very much either way, but it will vary quite a bit depending on the throttle opening used, probably doubling if you're nailing it...

That is why you need to do it over a large number of hours/litres because usage varies and you want an average. It is also difficult to measure exact amounts to top up if you are only putting a few litres in at a time.

However for a small yacht with probably only 50l tank and working on the typical 1l for that size engine, you only need to add fuel maybe 3 times a year.
 
Thank you all for your replies, you've told me exactly what I wanted to know, and it's a nice easy way to remember, about 1L/10HP/hr for cruising.
Thanks
John
 
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