1989 3760 cruiser fuel consumtion

Joined
Oct 13, 2018
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1
1989 cruiser 3760. Twin 454 crusaders. 2x 150gal tanks

recently purchased the boat and am getting to know it inside and out lol. Motors are great. Both running good. Changed everything I could and currently get 3600rpm on both engines at cruising speed. 26mph with a max of 33mph. No hiccups on the engines and sound loud and great.

I filled both tanks ($1900CAD) up full as my 1 fuel guage isn't working. And wanted to play it safe.

I went out 4 times since the fill. I realized today the tanks selector switch isnt working when i had the selector shutoff closed in the middle. I realized this as i ran the 1 one tank dry. (The tank that ran dry, the fuel guage is not working) To confirm that my other engine is still fuel on the guage.

my usage per day is: 15 mins cruising at 26mph for 15 mins. Fishing for 5-6hrs on one engine and then cruising back at 26mph for another 15-20mins.

So I used 37.5 gal of fuel per day. That's about 150liters approx ($247.50) per day.

this sounds crazy to me. Do these number sound correct to other cruiser owners?

thanks in advance
trevor
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,304
welcome aboard

boat motors burn 0.4# of fuel per HP per HR. this is the Brake Specific Fuel Consumption for a spark ignited motor.
2-stroke outboards are about 0.5# of fuel per HP per HR and diesels are at 0.33# of fuel per HP per HR

so you have two 350 hp motors and you were burning fuel at a rate of about 200hp each, or 400hp for approximately 45 minutes

that burned 120# of fuel, (0.4 * 400 * 0.75) or 18 gallons (120/6.7)

you were idling along at about 50 hp for 6 hours.

that burned another 120# of fuel (0.4 * 50 * 6) or 18 gallons

so yeah, that is what you burned

its not a Cruisers thing, its a boats suffer poor fuel economy PERIOD thing

your choices for fuel economy is to use a sail or a set of oars.


welcome to owning twin big blocks and paying for marina fuel.

BTW, you may want to check into having a fuel truck deliver fuel. its usually much cheaper per gallon than marina fuel dock prices.
 
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