Fuel consumption/economy of 21' cuddy with 4.3 Mrc

[martines]

Hy guys,

may be its been discussed many times,
but since friends of mine wanted to use the boat and I told them just to fuel it up, they asked me what is the consumption so they could plan their trip (there is 0 gas stations at the river where the boat is, so you need first to fuel it up manualy using 6-7 plastic 5 gallons containers, and after that you must carry the needed extra fuel WITH YOU at longer trips..., it looks like floating bomb sometimes so no smoking on board). Since I was not sure what it is precisely, yesterday I made two runs feeding the boat with small external tank with known fuel quantity and here are the results:



Previous owner gave me quite different numbers and I never checked, giving the overconsuption to overloading the boat with people and gear, rough weather, dirty carb.. etc.. Now after all is fixed (carb, filters, spark plugs, prop etc..) and the test run was with empty boat and only 2 people on board in nice weaher.
Is this a normal consumption for this boat and engine (1999- 21' bayliner 2052 cuddy, 4.3 with 2bbl, prop -4 blade amita 19p) ?

Best regards
Martin

 

[tpenfield]

picture did not come through . . . what were your results? I'm guesstimating 3-4 mpg at efficient cruise.

 

[jimbo_jwc]

http://www.boat-fuel-economy.com/

 

[martines]

picture did not come through . . . what were your results? I'm guesstimating 3-4 mpg at efficient cruise.

yep, nearly 3mpg, here is the picture again:



or in excel :

condition	RPM	speed, miles/h	gallons/min	gallons/h	$/min	cost $/hour	cost per mile	MPG
cruise	3300	28	0.174	10.5	1.16 USD	69 USD	2.48 USD	2.7
WOT	4500	41	0.264	15.9	1.75 USD	105 USD	2.56 USD	2.6
gas cost per gallon	6.63 USD

Nearly the same statistics here http://www.boat-fuel-economy.com/ so it seems fine . Thanks

 

[redneck joe]

I've never owned a 4.3, but the two 5.7's I've had (one in current boat below) I get that at cruise. Not sure at WOT I rarely run that. i would think a bit more?

 

[bruceb58]

I can get 2.8 MPG with the Wellcraft in my signature measured with a flow meter connected to a GPS that computes the MPG for me. I am thinking your data is off and it may have some error if you are doing it over a small distance.

 

[tpenfield]

with a 4.3L engine those numbers seem a bit low . . . My 7.4L with my 24 footer was in the 2.5 mpg range. Usually your fuel economy at WOT drops way down, but your figures do not show that . . .

So, probably some things to verify are . . .

Condition of the boat (excess weight/water in the foam, etc)

Accuracy of your measurement methods

 

[thumpar]

Why is the gas price so high?

 

[bruceb58]

Why is the gas price so high?

Check out his profile.

 

[sharkin95]

dump the 4 blade and run with a 3 blade 14.5 x 19 for a 2 or even a 4 barrel that's horrible. I have a 4.3 1997 Vortec heads 4 brl.Weber carb thunderbolt 4 ignition no mods pushing a 21' 1989 IMP Sportsman 220 3200 lbs. with canopy enclosure. My boat runs 3300 rpms 20-21 mph @6.3-6.5gal per hr. I top out at 35-38mph@11-12gph.@4600rpms

 

[Idlespeedonly]

Good job. Thanks for posting the info.

 

[achris]

I've done the charts for my boat, which is very similar to yours. Budget around 1.3 to 1.5 litres per nautical mile, and that's in the 2,000 to 4,500 rev range.

BTW, you know what they say about lending out your boat? "Never lend out your boat or your wife. They both come back the same way."

Chris.......

 

[martines]

Why is the gas price so high?

:mad-new: Thats the cheapest price at a gas station (not at marina) in EU, in the poorest of the EU countries . The diesel and the premium gas is additional round 25-30 cents. Therefore a big, especially gas engines are rarely used and are aslo cheap. Like 70% of the fuel prices are just taxes (20%VAT, another 50% duty, rest is green and environmental ones......). Speaking for cars: on top are the CIty taxes: for 3 liters engine it is up to 15 times higher than for 1.3 engine.....

Anyway, I friendly envy you guys for the fuel prices in US. Enjoy while you can :watermelon::watermelon: