Fuel Efficiency Question

My boat is just slightly out of your date range (1995 Ski), but has the GT-40 engine. I have kept pretty detailed logs on fuel usage since 2010. The boat runs 90% slalom between 32 to 36 mph, 5% barefoot runs, and very infrequently a joyride. Very rarely is the boat just idling for any period of time.

With that in mind, here are my numbers (approx. 50 hours per year). I'd be curious to see what others are getting.
2010: 3.89 gph
2011: 4.37 gph
2012: 5.16 gph (one faulty spark plug most of the year)
2013: 4.47 gph

Cooper

I have a '95 ski with the GT-40 EFI and I have noticed that when the little pointy thingy points to E, I fill it up and smile ear to ear again.

When you add up all that goes into boat ownership, the fuel cost is a minor item.

I have no idea on gph on my boat. As mentioned above, when the gauge gets low I add more.

Not to be flip about it, but I just don't care. For a ski boat, I would never choose the engine based on efficiency, just whether it's a good fit for the boat and my use.

As far as I know, the 351's will all burn about the same amount under the same load at same rpm. Carbed, injected, not sure there is a major difference in fuel burn.

Not that easy to answer because everybody's use may vary.
Fuel Injected EI motors will be more efficient than Carb EI
If you are primarily running heavy loads or barefooting a Big Block could be more economical.
The year range noted won't have many motor choices, most common will be small block efi (GT-40/Apex/Excalibur) the Big Block Python was available but pretty rare and the carb'd motor was a Pro Ski IIRC.

Seems the 351 in my SW is more efficient than the 360 in my Century but that may be a function of use...the Mark II is a little hot-rod and just begs to be driven as such. Anyone know any gph figures for 70's era engines?

Fuel cost is also an overall use figure. I calculated the to and fro fuel cost for a tow vehicle would exceed my monthly rack storage bill. Plus, it's hassle-free, and everytime I arrive at the lake to see it sitting at the dock, all ready to go,I'm like a little kid on Christmas morning

peter1234 wrote: i was amazed (thread jack non cc) bought a carbed 454 25 ft formula and have used it 4 times some full throttle some cruising and lots of no wake and have used $170 or so in fuel with the fun its been i would have paid 400.00   just find the boat you love and enjoy it

Peter, mechanical or vacuum secondaries? Sounds like a fun boat! I drove behind a newer Formula today on the highway, beautiful boat, looked to be about 35 ft.

I meant the Formula I saw looked to be 25 ft., not 35, can't see well enough on my phone!

Curious what you find with your prop. I wouldn't have thought a stock 454 would get a 25 ft. Formula up to 55, I believe that's a fairly heavy boat. As you know better than me, more HP is pretty easy to find on a 454! I'm beginning to catch the bug to do some salt water boating, I'm about an hour from the coast so well within easy trailer range.

ummmm... when it's empty, I fill it back up http://www.correctcraftfan.com/forum/smileys/smiley2.gif