Fuel consumption/mileage
 

Hi Guys, I've been kicking around making an exhumas bahamas run this summer in my 30' scarab. I didn't think my boat had the fuel economy to make the trip until yesterday when I took it out of mothballs and filled it up with gas. It only took about 26 gallons. That's what was used up after we filled up in bimini, and came back across to miami, then went back out and up to dania beach (about 65 miles altogether?). Which means I was getting like 2.4 mpg?? Is this possible? I was cruising at 3300-3500 with 4 people in the boat and some luggage. Motors are 489's with 25 pitch props. Either somebody put some gas in my boat when I wasn't looking or I'm getting some good mileage? Wouldn't 2.4 mpg cruising be very good? Thoughts and opinions welcome.

Pull some gas into a glass jar and see if you have water mixed in there!! I had an 1986 scarab 30' with twin 454's...would suck down an easy 50gallons+ running about 75miles round trip from the IL/WI border down to Chicago and back...i once tried to figure out what the "MPG" was on that boat for a summer....somewhere between .8 to 1.4 is what i got. :)

I was thinking I was getting about a mile to the gallon. Before I do any further planning on the bahamas trip I'm gonna put the same 4 people that'll be going on the trip with the same weight as luggage and cruise 50 miles and see what kind of consumption I'm getting. I just cannot convince myself I'm getting more than 2 mpg...

My 35 Nordic gets around 1.2mpg at a 50mph cruise. 2.4 sure sounds high to me.

It has Pfaff 700's. 565ci NA fuel injected. I built a blower motor last winter for my cat.

No kidding man. I have no recollection of putting gas in the boat. Me nor the guy that helps with the boat can remember us getting gas after the bimini trip. And the boat was flushed and winterized after that. I just don't see the boat getting 2+ mpg. I'm at a loss here lol.

My 1986 30 Scarab Panther gets 1-1.2 mpg,

A boat being filled in the water vs on trailer can take different amounts of fuel.
My boat will take on more fuel in the water(maybe 5 gallons or so per 80 gallon tank than when filled on land.

BTW, on calm water/light chop, I can get 1.5-1.7 mpg. Rough water will be closer to 1.2 mpg with twin 502mpi's in an 8k boat.

No way at 2.4mpg on Twin deep V. Last 4th I did just under 180 miles cursing the river with pull here or there. About 1.2 smiles pr mile. 502 mpi's, 33 Outlaw

Bingo. I bet that's the issue. This 300 sits a lot more bow high in the water than on the trailer and the fuel filler enters the tank at the front. It must have an air pocket at the rear of the tank. I'm going to take it back down to the store and jack the front of the trailer high in the air and see if it takes more gas. I'll report back later! lol

Be careful doing that. I filled my boat on land and then put it in the garage which has a slight forward slope. Ambient temp warmed up some and fuel started dripping out the vent tube.

Well it took right at 10 more gallons. I redid my math, it took 21.2 gallons the other day. (wasn't accounting for super being 3.02 here) so 31.2 gallons consumed on what I thought was about 65 miles, then I went on google maps and plotted the trip, it was actually 82 miles on 31.2 gallons of gas, for an awesome 2.6 mpg, which didn't happen. Somebody must have put some gas in my boat. It's a mystery.