340 6.2L fuel usage

[justgothere]

I have a 340, 2003 (new shape) with 6.2 engines.
we struggle to get less than 1.6 G/NM at 3800rpm which is about what we need to cruise at. Engines are healthy with very low hours (140hrs)
We cruise at 19kts and about and show 15 - 16 gph
8.1 engines tend to show about 0.94 G/NM so about 1/2 what ours is.
Does anyone have Data on the speed/ best fuel use etc as I can not find any data for these engines on the net.

Our gas is USD7.30 per gallon here in NZ so economy is an issue.

[skolbe]

15 to 16 hours per engine? That would be about right for that boat and engine combination at 3800 rpm's.

[jason78]

Our gas is USD1.95 per gallon here in NZ so economy is an issue.

Our gas is USD 4.00 per gallon here on the water.

[Bucit]

Our gas is USD 4.00 per gallon here on the water.

Ours is over $5.00 here. I have two friends with 2001 340's and the 6.2's. I think they get around .75-.8 gph at best. That boat (especially the newer style) with the 6.2's are way underpowered in my opinion.

[280DA]

Our gas is USD 4.00 per gallon here on the water.

Probably 1.95 USD /liter or 7.37 USD a gallon

[ardeprint]

If my math is correct you are not getting 1.6 G/NM. I could be wrong, but if you are averaging 16GPH your number should be 0.84G/NM withan average speed of 19kts. A few things could be wrong. Perhaps you are not really cruising at 19Kts. Is this from GPS or mechanical devise? Or simple you made a mistake on the math.

[Bucit]

I could be wrong, but if you are averaging 16GPH your number should be 0.84G/NM withan average speed of 19kts. .

Those figures are pretty close to the 2001 340 with the 6.2's i posted above. I would think the 2003 or newer hull would be even worse.

[justgothere]

Correct. Close to $7.30/gal US

[justgothere]

I would not have thought almost double the fuel use of 8.1 horizons

[justgothere]

Correction usd 7.30/gal