Outboard Fuel Consumption...

NETONE · 02-11-2004, 07:03 PM

Ok....some back ground, last week I took my boat, 21' Super Vee Pro with a 225hp Mercury, pump High Volume, out for a long run. I ran from Chinook Landing to St John Bridge & back. I ran between 5000 & 5400 RPM's. I fiqured I would burn some fuel, which was one of my goals besides fishing. Well, I burned 40 gallons....from my talks with the folks at Stevens Marine this was within the normal range based upon my need for RPM and speed. But WOW...with my boat being new I was blown away it was that thirsty...I fiqured it was consuming approximately 1 gallon every 3 mintues...I couldn't drink that much water in that time for a million bucks even on Fear Factor! I have been very reserved in my operations on other trips keeping it just on plane at 3000 to 3200 RPM...what a pig in the RPM jump....

So with you other folks that have big HP outboard pumps what what you seen in such RPM and running???

Silver Hilton · 02-11-2004, 07:30 PM

20 gph is well within range, though maybe a bit high. I suspect if you just backed off to about 4000 you'd see a huge jump, for not much loss in speed. I have a Sportjet 175, which will run 6-7 gph at 4200, and 13 gph at 5200.

crayfish69 · 02-11-2004, 07:40 PM

Was your 225 carburated, EFI, or was it an Optimax?

NETONE · 02-11-2004, 07:46 PM

I forgot, its a 225Hp, EFI, Saltwater...

I love my boat.......even if its a thirsty beast at 5000 RPM's....

NETONE · 02-11-2004, 08:05 PM

I understand that with the outboard pumps compared to the inboard sport jets or V-8's the outboards have to lift then spin the water to the outlet of the pump as compared to the Sport jets/V-8's where the flow is more in a direct line. This in it self would result in an increase in fuel consumption due to the physics involved...

ssteelheadsteve · 02-11-2004, 09:04 PM

In anything but the calmest water with no wind and a medium load you can expect to burn a gallon every mile. My 460 inboard jet gets a little better than 2mpg :smile: Yes I was happy to wave good by to my 225 hp outboard. 225 hp jet boat cost per day to go fishing ? No less than $150 per day. More if you travel far from home or dock.

Time Off · 02-11-2004, 09:18 PM

Look at the charts. Most motors the GPH rises dramatically after 4,000 RPM. This chart is for a 225HP in a 22ft boat.

RPM MPH GPH

IDLE 3.3 0.7
1000 5.0 1.0
1500 6.5 1.4
2000 10.3 2.5
2500 21.5 3.4
3000 28.0 4.6
3500 33.9 6.6
4000 40.9 7.9
4500 46.0 11.4
5000 49.4 14.2
5650 55.2 19.2