Range

[BeBalu]

how far will 25 gallons get a 25hp diesel pushing about 35 footer monohull. I know that there are several factors, but whats a safe guess? Lets assume a nice little 5 knots for the speed.

[pete33458]

a lot further than I'd ever want to motor...I would say at least several hundred miles.

[Cheechako]

.5 gal per hour is 50 hours motoring at 5 knots is 250 Kmiles.

[bstreep]

Originally Posted by Cheechako

.5 gal per hour is 50 hours motoring at 5 knots is 250 Kmiles.

What I'd guess. maybe more, with a clean bottom.

[delmarrey]

Depending on wind, current and boat weight/design I'd say more like 200 kt-miles. Then there is motor sailing. Too many variables to say.

[roger.waite]

A practical test is often best for answering this. E.g. fill the tank up, go cruising for a while logging engine hours (try to keep at the same sort of revs), speed & conditions, then see how much juice it takes to top up again. But the consensus from previous replies seems to be something in excess of 200nm, and much more if clean & sail assisted in light seas.

Manuals often have specific fuel consumption curves that you could use to estimate range. Such curves allow you to do much better than our guesswork. If yours has one, measure your speed at different revs and then work out e.g. range at 80% revs or revs giving you maximum range.

Just carry a jerry can if you don't know and are off on a long trip ...

[BeBalu]

Alright, good stuff. Thanks for the help. I really appreciate the helpful atmosphere this forum provides.