I usually figure any big block will get 2 mpg cruise and 1 mpg WOT.
So I'm considering a 26 Seebold Eagle w 2x454 and a 38 Scarab w 2x 540.

I'm figuring the Scarab a 9000# boat w 540s is going to burn a hella lot more fuel then the 26' pad V w 454s.
Any ideas or comments?
Thanks
Evan

The gas mileage factor was "nonexistant" until recently----now that gas prices are redicluous

It would be more (the 540) but its all relative to the force applied to the right hand .... ..... 454 carbs or MPI ? my 454 mags ..averaged about 12-15 GPH ... that's overall ... idle time ...cruise ...some WOT ...9000lb 311 ... they are out now being upgraded to 509's ...will be interesting to see the difference ......m

Gasoline consumption is related to horsepower.A certain amount of power requires a certain amount of fuel to make that power.A 454 making 500 hp at WOT for an hour will use 220 lbs of gas/7 =31 gallons of gas.
A 540 making 600 hp at WOT for an hour will use 280 lbs of gas/7 =40 gallons of gas.In some cases like a 525 Merc that has a very rich tune-up could burn more fuel than a 600 or even a 700 hp engine

yea ???? well whata you know ????

Scary ......... les see ....80gal x 3.23 = 258.00 ....crap!

so any motor not jetted right is costing $$$ ....

You got that right

Go to www.boattest.com and find your boat, or as close as you can come. From what a have found, 454s best, is at 2700-2800 rpm's and with twins it's like 1.75 mpg.

If you are interested in a 26' boat, why not look a something with twin small blocks?

I'm not questioning your numbers but I have heard that it takes approx 1 gallon/hour to make 10 HP, so a 500 horse motor would be 50 GPH at full throttle. Maybe this is only true for the over rich factory motors?
I know that this is fairly correct on 2 strokes, as 300X's burn 32 GPH at full throttle.

Also would it be true that if you had a 500Hp 454 and a 500 Hp 540 both tuned correctly that they would both consume the same amount of fuel at WOT?

I was kind of wondering the reason for twin big blocks in a 26 footer myself.