fuel consumption?

[jafo9]

so i was at my local costco today and a local marina was having a "boat show" with special member pricing. we looked long and hard at a few aqua patios. wow, very nice boats. until now, we had our hearts set on another I/O, just one with 5 liters and 3 toons. they are very hard to find and always priced in the stratosphere. the salesman stated that the outboard 4 strokes were quieter and got much better fuel milage. is there truth to this? thanks.

[jim454]

Best I have done so far is a gallon and a quarter an hr.

I'm running an 18 ft with a 50 honda 4 stroke. oh, and I average about 7 miles distance in that givin hr.

Hope that helps.

[HandymanHerb]

The 2 stroke E-TEC is quiet and gets good fuel mileage too.

[dockholiday]

I know they have some gph figures on 2 strokes (opti) and the 4 strokes not sure about the stern drives I/O's. Should be able to get some fairly good comparison in a given hp range.

http://www.mercurymarine.com/engines/index.php

My take is in a given hp range the 2 stroke will give the best speed, given it is lighter of the three typically. The 4 stroke will be somewhat quieter although the 2's noise level has been coming down every year. My 150 is more quiet than my old 90 .Think that is where the saying different strokes for different folks ie 2 or 4 strokes.

[MrGadget]

Fuel consumption depends a lot on how you drive it too. As obvious as that sounds, the next part of that may seem less obvious...for some boat/motor combinations, faster is better in terms of miles per gallon (not necessarily gallons per hour). Go fast boats skipping along on plane at 80% throttle in my own little experience get better MPG than when they're plowing along at 20% throttle.

With pontoons, I would think it is really going to be the boat + motor combination to answer your question, and various manufacturers should have data on what they've tested together.

Since mine is custom, big, and heavy, this will have little relevance to you, but for the curious, at 70% throttle I get about 3 mpg from my E-Tec 250, or 5 gph consumption. I haven't yet exhaustively tested consumption across the range, that's just for the ~15mph at which I enjoy cruising along.

[jafo9]

i certainly understand that every boat/motor combo will have a sweet spot. it still amazes me that an off shore boat may have that sweet spot at 50-70mph.

my biggest question was whether a OB 4 stroke would be more fuel efficient than an I/O 4 stroke, which is what the salesman was telling us. My first thought was that he didn't have any I/O's to sell and he wanted to direct us to an OB.

so, for the same hull, with say a yamaha 150 vs. a 5.0L MPI Mercruiser. what are your thoughts about fuel efficiency. what about noise?

[jim454]

I would most certainly say yes, but I can't back that up.

I think 4 strokes and pontoons go together like bread and butter.

My honda runs so quietly at idle that there are times that I have to check the tach to see if it's running. That's a big deal if you are entertaining guests and want to carry on a conversation.

[OldePharte]

i certainly understand that every boat/motor combo will have a sweet spot. it still amazes me that an off shore boat may have that sweet spot at 50-70mph.

my biggest question was whether a OB 4 stroke would be more fuel efficient than an I/O 4 stroke, which is what the salesman was telling us. My first thought was that he didn't have any I/O's to sell and he wanted to direct us to an OB.

so, for the same hull, with say a yamaha 150 vs. a 5.0L MPI Mercruiser. what are your thoughts about fuel efficiency. what about noise?

An I/O could be louder than an outboard, depending upon the muffler. We have some go fast pontoons on our lake and if your eyes were closed you would be hard pressed to tell, from the rumble, what you were listening too was a pontoon or a go-fast boat.

You really need a test drive in your two desired options. Top end speed could be different due to lower unit gearing.

Since you are in Alabama winterizing probably isn't an issue. But I would think that servicing would be a lot easier with an OB than an I/O. But then I am not a mechanic.

I see that the Honda is not an option. As stated previously, my 150 Honda is super quiet and even at speed I hear more wind and water noise that engine noise. I haven't been around the Yammy 4 cycle for comparison.

I wish my Costco had a "boat show." Due to investment returns, we decided to go with 5% financing through Honda for our 'toon. That and the dealer gave me one heck of a discount for end of model year close outs.

[dockholiday]

OP did you ever get another prop or are you still running the aluminum?
doc

[OldePharte]

OP did you ever get another prop or are you still running the aluminum?
doc

Still runnin with the SS that came with the boat. I don't have 20 hours on it yet so haven't really been able to open it up.

[dockholiday]

OP did you ever get another prop or are you still running the aluminum?
doc

Still runnin with the SS that came with the boat. I don't have 20 hours on it yet so haven't really been able to open it up.

My mistake thought it came with aluminum
doc