Mercruiser 5.7 v8 aplha one consumption

Hello,
Ive been watching for a long time the forum but this is my first post.
Im about to buy Searay 22' br (1993 model) with a Mercruiser 5.7 V8 Alpha One GEN 1. The boat is in excellent condition and it seems like a very good deal for the asking price. The only thing that im worrying is the fuel consumption.. I asked the owner and he said that he hasn't calculate it but its around 1.5lt/m (0.39 GPM) at cruise speed around 25. What do you guys thing?

Thank you

Re: Mercruiser 5.7 v8 aplha one consumption

TheCramps said:

Hello,
Ive been watching for a long time the forum but this is my first post.
Im about to buy Searay 22' br (1993 model) with a Mercruiser 5.7 V8 Alpha One GEN 1. The boat is in excellent condition and it seems like a very good deal for the asking price. The only thing that im worrying is the fuel consumption.. I asked the owner and he said that he hasn't calculate it but its around 1.5lt/m (0.39 GPM) at cruise speed around 25. What do you guys thing?

Thank you

Click to expand...

Ayuh,.... I think somethings Fishy,... That hull was built 2 years after the intro of the Gen.IIs....

As far as fuel use, it takes X number of btus of energy, to move a load, regardless the motor employed...

Re: Mercruiser 5.7 v8 aplha one consumption

TheCramps said:

Hello,
Ive been watching for a long time the forum but this is my first post.
Im about to buy Searay 22' br (1993 model) with a Mercruiser 5.7 V8 Alpha One GEN 1. The boat is in excellent condition and it seems like a very good deal for the asking price. The only thing that im worrying is the fuel consumption.. I asked the owner and he said that he hasn't calculate it but its around 1.5lt/m (0.39 GPM) at cruise speed around 25. What do you guys thing?

Thank you

Click to expand...

. . . 0.39 gpm = 2.5 miles per gallon (US) so, that is about right.

Re: Mercruiser 5.7 v8 aplha one consumption

Thanx for your answer Bond-o . Im not sure that its a GEN 1. Im just guessing it cause i forgot to ask. I will go again next week for a test drive and i will see what actually is. So you believe that it could be GEN II? I read in the forums that GEN I and II is about the same with some minor differences like bigger impeller and stronger gears in the GEN II.Correct me if im wrong..
tpenfield thanx too for your answer. So you believe 2.5 MPG is reasonable for this old motor/ boat combination ?

Re: Mercruiser 5.7 v8 aplha one consumption

Yes, I get about 2.0 MPG with 24 foot boat and 7.4L engine.

Re: Mercruiser 5.7 v8 aplha one consumption

my 19' searay could get 3.5 mpg at 3000/30mph cruising. however that was with perfect conditions. most of the time about 3. so your 2.5 is good.

Re: Mercruiser 5.7 v8 aplha one consumption

TheCramps said:

... but its around 1.5lt/m (0.39 GPM) at cruise speed around 25. What do you guys thing?

Thank you

Click to expand...

I think that sounds pretty good. Mine (in my signature) uses about 1.25l/nm at that speed.

Agree with Bond-o... Strange to put an older engine in a boat...Usually people are pulling the original engine and putting something newer in...

Chris.......

Re: Mercruiser 5.7 v8 aplha one consumption

The OP isn't sure if it's a GenI or GenII. It's a 350, don't expect 40mpg. Boats burn plenty of fuel and your right hand determines how much fuel you will burn. Lots of guys complain about fuel consumption, when pressed, you end up finding out that they've got their boat running at or near WOT, what do you expect?? Don't run the snot out of your boat and it won't be too bad.

Re: Mercruiser 5.7 v8 aplha one consumption

TheCramps said:

The only thing that im worrying is the fuel consumption.. I asked the owner and he said that he hasn't calculate it but its around 1.5lt/m (0.39 GPM) at cruise speed around 25. What do you guys think?
Thank you

Click to expand...

I think if you're worried about fuel consumption, are you really ready to buy a boat? While the other guys provided some nice tech specs, I'm with bnicov about that should be the least of your worries. It's a sport boat meant to go fast, the faster you go, the more gas it will use. My right hand governs the speed based upon water, weather and boat mechanical condition not about getting 1.2 mpg vs 2.1 miles per gallon. When I'm out on the water, especially going fast, I have enough to watch out for and worry about without thinking of mpg.
fwiw

Mark

Re: Mercruiser 5.7 v8 aplha one consumption

Guys thank you all for your answers!
As you can understand im a bit new to all of this.
I had a 4.80m with an 70HP yamaha 2stroke outboard engine and now im looking for an update thats why i ended in this boat.
Anyway MarkSee your are right about the fuel consuption..maybe i said it wrong, im not only worrying about the fuel consumption but i didnt had any idea of what mpg this engine/boat has. Also i agree that mpg is up to your right hand thats why ive asked for the mpg at the boats optimal cruising speed.
@bnicov as far as i know the guy that selling the boat, hasent changed the motor and the outdrive so its the "original" that Searay had, i found that Alpha I GEN II started the production at 1991 so its pretty logic to me a 1993 model boat to have the Alpha I GEN II.The guy told me that its the Alpha I, but i forgot to ask if its gen I or II.

Something else now..a bit out of topic about the consumption.
In which specific parts of this particular engine and the outdrive should i pay closer attention before buying this boat?
Im thinking of bringing a Mercruiser technician in order to check it but i want to know personally some thing before i do that.

Thanks for the help again.

Re: Mercruiser 5.7 v8 aplha one consumption

Consider getting a full survey done on the entire boat, not just an engine check.

CHeers

Re: Mercruiser 5.7 v8 aplha one consumption

TheCramps said:

Im thinking of bringing a Mercruiser technician in order to check it but i want to know personally some thing before i do that.

Click to expand...

Very smart of you to want to do that. You might want to call around to local shops and see what their pre-sales check entails as some may do a very quick check while others take more time, do compression tests, maybe even pull the drive off (that assumes the seller will let them).
Just start reading through these forums on others that have asked the questions on what to look for and you'll find a ton.

Mark