Number of hours per gallon?

[spartanpele]

1994 Four Winns, 3.0L, VP...28 gallon gas tank.

Kind of a strange question, but I'm curious as to how long I can expect to cruise around the lake if my boat is full up on gas when I start?

Is there a formula for hours per gallon? I realize that it depends on how many people in the boat/weight, how fast we're cruising around, etc. I'm just looking for a ballpark idea... 8 hours?, 10hrs? 12+hrs, etc.

Thanks

 

[tommays]

Re: Number of hours per gallon?

You will get ABOUT 2.5 to 5 miles per gallon BUT you really need to keep track as every boat and how it is driven is different

Tommays

 

[RubberFrog]

Re: Number of hours per gallon?

It also depends how big your tank is as to how many hours you can be out.

You can easily calculate this yourself. Fill the tank. Go cruise for three or four hours taking note of your average speed, amount of time spent idling and how hard you are hitting the throttle. Then fill the tank again.

 

[BrianS.]

Re: Number of hours per gallon?

He stated it was a 28 gal tank.

 

[KaGee]

Re: Number of hours per gallon?

I would kill for "Hours per Gallon".

8)

 

[spartanpele]

Re: Number of hours per gallon?

I found some information on another forum....

For the 3.0L (4 cyl):

Gallons per hour (cruise): 3.5
Gallons per hour (average): 2.3

For my situation...28 gallon tank...that works out to about 8 hours (cruising around); 12+ hours average (must be cruising and idling).

So...on a full tank of gas I should be able to use the boat for about 8-12 hours per fill up.

Thanks all....

 

[tommays]

Re: Number of hours per gallon?

I have had a 3.0 powered boat for 11 years your not running 8 hours on a 28 gallon tank unless you just trolling


5 gallons per hour at 25 MPH is 5 MPG which is about the very best you will do

I have taken many LONG trips of over 100 miles and am very sure of this

You "might" get 5 hours and use 25 gallons which pretty much leaves you empty as at least 2 to 3 gallons is not comeing out of the tank

Tommays

 

[calwldlif]

Re: Number of hours per gallon?

To clarify
it is gallons per hour.
Generally a motor is rated at
gallons per hour at WOT.
This it the worst case senario.
your motor is (I guess) @ 5 gallons
per hour at WOT, so 28 gal div by 5
= 5.6 hours
That is based on 28 usable, prob 25 usable
so 5 hours use.
So you won't be at WOT all day, so you should
get 8 hours.
My particular motor uses 6 gph with 36 gallon
tank. I use gage and general hours to fig
max distance and range.

 

[tommays]

Re: Number of hours per gallon?

Test Power: 1 x 135-hp MerCruiser 3.0L

RPM MPH Total GPH
800 4.0 0.6
1000 5.3 0.8
1500 6.5 1.2
2000 8.1 2.4
2500 17.8 2.9
3000 24.5 3.9
3500 29.3 6.10
4000 33.8 6.7
4500 39.1 8.4
4900 43.7 12.3

This test is from and empty 17 ' boat its usefull because the boats range goes up and down from 55 miles at 2000 rpm to 103 miles at 3000 RPM

http://www.boattest.com/boats/434/test_results.aspx

Tommays

 

[Scaaty]

Re: Number of hours per gallon?

NO ONE can figure this out....jeezzz. To many damn variables. Tides, wind, current, weight, different # of people in the boat, ....got a gas Gauge? it will tell ya a hell of a lot more than we can

 

[calwldlif]

Re: Number of hours per gallon?

12 1/2 gallons per hour?
WOW
I am surprised.
I know of 150 hp motors only using 8-9 gpm

 

[zshooter]

Re: Number of hours per gallon?

I agree with Scaaty - too many variables for us to know about your setup.

The best way to figure it is to keep careful data (on a notepad or something) of hours used, type of use and gallons used. Over time, you'll know what you are using.

My '86 140 Alpha One is unbelievably efficient for our purposes. We can ski/wakeboard easily for 4 to 5 hours on a 1/2 tank of gas (20 gallon tank). The humans are tired long before the boat runs low on gas!

 

[DayCruiser]

Re: Number of hours per gallon?

Ya, I have found that wind and weight and speed changes everything. Sometimes when I go out, I get better gas milleage than the last time out. I usually travel at the same speed. Put putting along to save gasd most of the time.
No matter what. 3$ a gallon gas sucks.

 

[KaGee]

Re: Number of hours per gallon?


if you REALLY want peace of mind... buy a FLOSCAN.

 

[Silvertip]

Re: Number of hours per gallon?

Tommays numbers are the best of the bunch. The old rule of thumb is to insert a decimal point one number to the left in the horsepower rating. 130 HP = 13.0 gal/hr at WOT. In his chart 4900 RPM (wot) showed 12.3 gal/hr. Not far off. It takes so much fuel to make so much horsepower. Obviously that rule can't work at anything under WOT.

 

[jka]

Re: Number of hours per gallon?

It is so variable depending on speed, load, wind, etc. Here's 4Winns site. look under fast facts. You'll find it....
http://www.fourwinns.net/

 

[JoJoBetsy]

Re: Number of hours per gallon?

Are you running synthetic or dino oil?

JUST KIDDING!!! :devil:

The voodoo mathematics of fuel consumption on the water is better left to engineers whose time is mostly spent wishing they were on the water.

 

[Boomyal]

Re: Number of hours per gallon?

if you REALLY want peace of mind... buy a FLOSCAN.

What about a NavMan KaGee?

EDIT: Brunswick/Navman just answered this question. Although the price is attractive, this unit (navman 2100) is a joke. It plainly states on their spec sheet that this unit is suitable for carburated, 4 stroke engines from 90 hp up to 300 hp. Then they go on to state that the units fuel flow rate range is 1.3 gpm to 35 gpm.

Obviously, the low end is way over the idle consumption of your typical under 300 hp I/O engine. I called their tech dept and they said "yep, you'll loose a lot of fuel consumtion data at idle. These units were made when motors were not as efficient,(crock) and there are no plans to modify the range registry"

I told him that my mid 70's 302 was not exactly a 'newer efficient' motor but most likely only burned 1/2 gallon a minute at idle. In essence, he said tough luck.

What a joke?

FWIIW, Floscan costs over twice as much as the Navman and requires a much bigger hole in the dash.:'(

 

[Boomyal]

Re: Number of hours per gallon?

^bump

 

[KaGee]

Re: Number of hours per gallon?

You meant GPh didn't ya??

You wrote GPM.... at that rate my 90 gal tank wouldn't last long trolling!