Boats on Used Victoria and Other Areas

Sir Reel said:
It’s actually 197 US gallons and 164 imperial gallons hence the confusion.

My twin diesel 30 uses about 14 gph running at 35mph which gives me a range of about 360 miles.
Which gets me from Vancouver to Bamfield and back. For a boat it’s weight, size, and versatility it’s pretty good.
Still kinda hurts to fill up a 100+ gallons though.

Do v8’s in a twin install actually burn 12 gph each? I’m think more 16 to 20 gph. RC what did your single Bayliner burn?
Click to expand...
It was only a 5.0L in a 6500lb pig but I ran it at 3800 rpm to go 30 mph burning about 14 GPH
 
Sir Reel said:
It’s actually 197 US gallons and 164 imperial gallons hence the confusion.

My twin diesel 30 uses about 14 gph running at 35mph which gives me a range of about 360 miles.
Which gets me from Vancouver to Bamfield and back. For a boat it’s weight, size, and versatility it’s pretty good.
Still kinda hurts to fill up a 100+ gallons though.

Do v8’s in a twin install actually burn 12 gph each? I’m think more 16 to 20 gph. RC what did your single Bayliner burn?
Click to expand...

General Rule of Thumb for gas engines each at cruise;

4,3L 7gph
5.0L 10 gph
5.7L 12gph
7.4L 15gph

For diesel, HP of motor, divided by 20, less 20%. So a 400hp should burn 400/20 = 20gph, less 20% = 16gph, at cruise (RPM 10% off the WOT rpm).

 
BCI said:
General Rule of Thumb for gas engines each at cruise;

4,3L 7gph
5.0L 10 gph
5.7L 12gph
7.4L 15gph

For diesel, HP of motor, divided by 20, less 20%. So a 400hp should burn 400/20 = 20gph, less 20% = 16gph, at cruise (RPM 10% off the WOT rpm).
Click to expand...
Assuming what boat weight?
 
My 320hp VP is about 7 gph at cruise of around 20 knots at 280p rpms. It will boot along much quicker but no thanks too much junk in the straits. Plus I'm not sure who all these 30 knot guys are, I'm out all the time and no one seems to be ripping by.

There was this one dude on a bayliner once lol
 
Rain City said:
Assuming what boat weight?
Click to expand...

Assuming your power package is propped correctly for your boat weight (meaning you can reach proper WOT rpm as per manufacturer), and you operate within the normal cruising RPM.

For normal fast-cruise RPM, that would be around 3500-3600rpm for 5.0L and 5.7L, and 3200-3400rpm for 7.4L. I have not owned the 4.3L but I understand it revs higher at it's normal cruise rate.

If you want to go and take a look at some fuel consumption figures for various gas I/O's, propped correctly (i.e. to reach proper WOT RPM for the weight of your boat), you can scroll through a bunch of engine configurations here, and you can cycle through different RPMs.

I find it to be very accurate based on my own first hand experience with the same power packages.

Here's the link for the 5.0L 260hp configuration. From that page you can bounce around and pick difference displacement, horsepower configurations, as well as operating RPM for each;

http://www.boat-fuel-economy.com/mercury-mercruiser-5.0-305-260-fuel-consumption-us-gallons
 
Last edited:
BCI said:
Assuming your power package is propped correctly for your boat weight (meaning you can reach proper WOT rpm as per manufacturer), and you operate within the normal cruising RPM.

For normal fast-cruise RPM, that would be around 3500-3600rpm for 5.0L and 5.7L, and 3200-3400rpm for 7.4L. I have not owned the 4.3L but I understand it revs higher at it's normal cruise rate.

If you want to go and take a look at some fuel consumption figures for various gas I/O's, propped correctly (i.e. to reach proper WOT RPM for the weight of your boat), you can scroll through a bunch of engine configurations here, and you can cycle through different RPMs.

I find it to be very accurate based on my own first hand experience with the same power packages.

Here's the link for the 5.0L 260hp configuration. From that page you can bounce around and pick difference displacement, horsepower configurations, as well as operating RPM for each;

http://www.boat-fuel-economy.com/mercury-mercruiser-5.0-305-260-fuel-consumption-us-gallons
Click to expand...
Oh right that makes more sense now. I guess the other variable when you get more and more underpowered is how fast it gets on step. So although fuel consumption might be the same at cruising speed you'll be less and less efficient as your boat gets harder and harder to pull out of the water. Or is it the other way around? o_O
 
The longer you spend pushing water trying to pull the boat up out of the hole and onto plane, the more fuel you'll burn and the harder it is on the engine and the driveline. However, if you prop accordingly, you should pop out of the hole in a reasonable time. Where you'll see the biggest difference in fuel consumption on larger heavier boats is that your cruise speed will be lower than a small boat of the same horsepower. Essentially because the heavier boat spins less pitch when using a same horsepower engine as a smaller boat. Think of it like driving around in first gear in a tractor versus 3rd gear in a regular car of the same engine size.
 
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