Fuel Consumption expectation?

rhino_160

Seaman
Joined
Nov 10, 2013
Messages
63
Hey all,
I may be giving up my 2010 Manitou Oasis Pontoon with 70hp Suzuki Fuel Injected Outboard for a 2007 Tahoe 222 with Mercruiser 5.0 260hp. Now, I know the fuel mileage isn't going to be anything like it was on the pontoon (top speed at 18-20 mph). My question is what can I expect on the Tahoe if I am leisurely riding around the lake on it, say 25-30 mph on average with 4 adults and a couple coolers. I know it will run around 50 mph but that's not my question here. We normally ride about 20-25 minutes then anchor for 2 hours, repeating this process for an 8 hour day. I am just wanting to get an idea of what to expect Thanks
 

garbageguy

Lieutenant Commander
Joined
May 8, 2012
Messages
1,531
My 1998 24 ft small (exprress) cruiser (fairly heavy) with a carb'd 5.7 averages 5-7 gallons per hour all-around while running (not at WOT)
 

Watermann

Starmada Splash of the Year 2014
Joined
Jan 12, 2013
Messages
13,747
Relying on a guys internet guess isn't the best way to determine fuel consumption. Knowing the tank capacity is the main thing and having an accurate gauge. I'm also having to guess you're worried about running out of fuel? The best way know what she'll consume is to fill her up and go boating!
 

Slip Away

Lieutenant
Joined
May 11, 2010
Messages
1,431
Always amazes me why people wonder about fuel useage on a powerboat. If it is really a concern you might want to find another hobby.
 

rhino_160

Seaman
Joined
Nov 10, 2013
Messages
63
i wonder about fuel usage because i like to plan ahead and make sure i don't need to fill up everytime i go out or can i run an entire weekend based on my driving habits? I have never owned a power boat, just a pontoon. I know that with 30 gallons on it i could go 4 days on a tank with my driving habits. I wanted to have a somewhat basis of knowledge about this new boat as compared to the entirely different boat i currently have. I also inquired about fuel consumption on this boat because with more speed, i can go a further distance, but at a cost. i would like to tour my entire lake from one end to the other, but need an idea on fuel consumption for this. I have not purchased the boat yet so I am unable to run it out and see the consumption rate. Just hoping to get a couple people with a boat similar to a 2007 22' Tahoe running the 5.0 to chime on their experience, not looking for 100% accuracy. Thanks in advance all
 

Mischief Managed

Lieutenant Commander
Joined
Dec 6, 2005
Messages
1,928
If it really tops put at 50, it will do 35 MPH at 50% power burning 10.4 GPH, so that would yield 3.36 MPG. Assume 3 MPG in the real world and you'll likely have plenty in reserve. Keep it cleanly on plane for best fuel mileage.
 

KD4UPL

Senior Chief Petty Officer
Joined
Feb 13, 2010
Messages
653
My 20.5 Larson with a 5.7 uses about 20 gallons a day. My driving practice is very similar to yours but I usually have twice as many people on board. The tank holds 40 gallons. If I'm out for a long weekend (Friday evening thru Sunday afternoon) I burn the whole tank.
 

rhino_160

Seaman
Joined
Nov 10, 2013
Messages
63
thanks all for the replies. I go pickup the Tahoe this coming weekend as I sold the pontoon this past wknd. I will give the engine a good testing as it is warrantied for 90 days but other than that I will cruise at the 25-30 mph range. I think i will be satisfied with the fuel consumption being that i can cruise at 2500 RPMS at a higher speed that the pontoon could at 6000 RPM and only 20 mph.
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
I have a 40 gallon tank but still fill up before every outing in case we want to have more fun.
 

roffey

Commander
Joined
Nov 22, 2012
Messages
2,187
thanks all for the replies. I go pickup the Tahoe this coming weekend as I sold the pontoon this past wknd. I will give the engine a good testing as it is warrantied for 90 days but other than that I will cruise at the 25-30 mph range. I think i will be satisfied with the fuel consumption being that i can cruise at 2500 RPMS at a higher speed that the pontoon could at 6000 RPM and only 20 mph.

I have a 20 footer and it will do about 55 mph. I love to cruse up and down the lake at about 35 mph but the boast calls out to me once in a while pleading to open it up and just rip it down the lake as fast as i can push it, but then my other side tells me just cruse it, take it easy. LOL. Enjoy it.
 

Chad Flaugher

Petty Officer 1st Class
Joined
Jan 2, 2015
Messages
392
My old boat (1974 5.0L V8 190 HP tri-hull) will burn up 30 gallons in a day easy. We run her pretty hard, 7 people, pulling tubes a lot. "Slip Away" makes a good point. It costs money, I accept that. You'll have to do the same! Totally worth every penny in my books.
 
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