V8 vs V6?

scully222

Seaman Apprentice
Joined
May 1, 2007
Messages
33
I'm going to buy a bigger boat and have settled on a 21 ft bowrider. I see some come with a 4.3 V6 and others with V8. I'm worried about spending too much $ on gas with the V8. Would there be a huge difference? V8 gives more power, so less gas to get moving or go with the V6?
 

Bronc Rider

Petty Officer 1st Class
Joined
Sep 1, 2009
Messages
255
Re: V8 vs V6?

21' is too big for a v6. The gas consumption will not be very different between the v6 and v8.

EDIT: What engines are we actually talking about?
 
Last edited:

arks

Lieutenant Commander
Joined
Nov 7, 2002
Messages
1,929
Re: V8 vs V6?

The smaller engine, while more fuel efficient, will need to work harder to get the boat on plane and keep it there. The V8 will not need as much throttle to achieve the same performance.
The fuel economy difference should be minimal IMO- and the V8 will always have that 'little extra' when you want it.
Resale will be easier with the big engine as well.
 

drrpm

Senior Chief Petty Officer
Joined
Oct 24, 2008
Messages
707
Re: V8 vs V6?

Go for the V8. I have a 20 foot bowrider with a mercruiser 5.0 L EFI engine. It performs very well. The 4.3 EFI would probably be OK, however I frequently have 8 people + gear on board and pull a tube or wake boarder so the extra power is nice. A boat is really a toy and gas is a minor expense overall so you might as well enjoy it. Also, if you ever want to sell it the bigger engine is a plus.
 

AngelC

Petty Officer 2nd Class
Joined
May 28, 2008
Messages
189
Re: V8 vs V6?

I would definatly recommend you go with the V-8..I too have a 21ft Larson bowrider with the 305 V-8 and it's actually not bad with gas. I know the term V-8 scares some, but like I said it's not bad...unless!! your flooring all day long, then of course you will burn right threw a tank fairly quick. I usually cruise at about half throttle, and some runs at full throttle, but for the majority of the time it's cruising with the kids on the tube, or just running around. Go with the V-8, the power is NICE!!:D
 

allpoints360

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
342
Re: V8 vs V6?

I would try to get the most HP the boat was rated for. You'll be happiest in the long run.

When your loaded down with 5 people and trying to pull up a skier, you won't be thinking about your fuel economy.

Or maybe you will? Ha!

Good luck.
 

roadrunnr

Petty Officer 3rd Class
Joined
Sep 15, 2007
Messages
99
Re: V8 vs V6?

It depends upon how fuel is delivered. A 4.3 carbed engine - 190hp, 5.0 V8 carbed engine - 220hp. A fuel injected 4.3 - 220 or 225hp depending on whether it's a merc or vp. Fuel injected 5.0 is 260 hp, I believe. If the choice was between a carbed 5.0 or fuel injected 4.3, I would go with the V6. I would stick to the 220hp engine or above with that size boat, if it's fuel injected even better! Just remember wishing you had more power on a new boat you just purchased will leave you wishing you purchased a different boat!
 

rbh

Fleet Admiral
Joined
Mar 21, 2009
Messages
7,939
Re: V8 vs V6?

"There is no replacement for displacement"
350 sbc, 260-350 horseys
lots of them, reasonable part costs and good availability:D
rob
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: V8 vs V6?

There are lots of resources on the net where you can look up actual boat gas mileage numbers as opposed to claims in a forum. Mercruiser and Yamaha have excellent tests of different boats and motors, and Boattest.com is very good.

I put together the chart below when I was looking for a 22'-23' Bowrider. In the real world you're going to get 3.5 to 4 MPG in that size boat as long as you are cruising around 30 MPH, no matter which engine you have in it. As a general rule, the bigger motors have more torque available across the powerband which translates into greater acceleration if you want to nail the throttle.

BoatMPG.jpg
 

Bronc Rider

Petty Officer 1st Class
Joined
Sep 1, 2009
Messages
255
Re: V8 vs V6?

It depends upon how fuel is delivered. A 4.3 carbed engine - 190hp, 5.0 V8 carbed engine - 220hp. A fuel injected 4.3 - 220 or 225hp depending on whether it's a merc or vp. Fuel injected 5.0 is 260 hp, I believe. If the choice was between a carbed 5.0 or fuel injected 4.3, I would go with the V6. I would stick to the 220hp engine or above with that size boat, if it's fuel injected even better! Just remember wishing you had more power on a new boat you just purchased will leave you wishing you purchased a different boat!

An mpi 4.3 is better than a carb 5.0 in my opinion. Thats why I asked which engines were in question. For the most part you cant go wrong with a v8 but, I wanted to know how the v6 was set up. If we are talking about a 4.3 vs a 5.7 its the 5.7 thats the better engine (actually the same engine plus two cylinders). Here is a thread where we were comparing 4.3's to 5.0's. I wouldn't consider a carb 5.0 if I had the choice of a mpi 4.3 engine.
http://forums.iboats.com/showthread.php?t=354595
 

Snobike Mike

Petty Officer 1st Class
Joined
Sep 30, 2009
Messages
363
Re: V8 vs V6?

If you are worried about the gas maybe you should reconsider the whole boat thing. Gas is a fairly small expense in the overall scheme of owning a boat.

Bigger is always better. For a 21 foot boat I would get a fuel injected V8. Anything smaller and you'll be a sad boater.

Cheers.
 

mike343

Petty Officer 1st Class
Joined
May 4, 2009
Messages
284
Re: V8 vs V6?

IMHO a fuel injected 5.7 would be the way to go if you are going to keep the boat a long time. Our 4000# deckboat runs at 30 mph, heavily loaded, at just over 3000rpm--engine is loafing.
 

werthert

Petty Officer 1st Class
Joined
Jul 4, 2009
Messages
209
Re: V8 vs V6?

I am no expert but I would think parts are more readily available for V8s, more of them out there I would think.
 

WAVENBYE2

Lieutenant Commander
Joined
Apr 28, 2007
Messages
1,636
Re: V8 vs V6?

The 4.3L in my boat works just fine a 20', but the 21' I would go with a V8, it wouldn't have to work as hard to get the speed or get it up on plain. For my set up a V8 really isn't neccessary, I run around all day, beaching and the trip back to the ramp on a 1/2 tank ($40) but thats for my set up with just the wife and I and our two dogs, no tubing or extra weight.
 
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