Older twin Yamaha fuel economy

Dave M · 07-12-2003, 09:25 AM

Ran the boat yesterday and burned approx. 65 gallons with the trip lenth of 103 miles ( not nautical).Is this good fuel economy for twin 1990 Yam 150s on my Grady? We were loaded with 150 gallons of fuel and about 450lbs of gear/people.
Most of the day was 1-2 with about 25 miles of 3-5 footers.
Thanx Dave

Grady White 242GT Offshore http://members.fishingworks.com/E150/

horseradish · 07-12-2003, 01:29 PM

That's 1.58 mpg. Not bad but not terribly good either! That's a heavy boat to push thru 3-5 footers. You could have gotten better mpg by going faster but you and the boat would have taken a beating. The goal should be to get close to 2.0 mpg.

Pursuit 2470, Twin Yam 150's

PeteH · 07-12-2003, 02:01 PM

About what I get with a full load. 3 guys, ice, tackle, 200 gal fuel, etc. Boat is a 1987 mako261 with twin 1997 200 yamis. I average 1.65mpg with the enclosure on the ttop running @ 4200rpm. If I take the enclosure off and cool down to 3800 I can get 1.8mpg. I have my engines mounted very hiogh on the transom turning 17p yami stainless.

Dave M · 07-12-2003, 02:21 PM

Thanx guys I really dont pay to much attention.. but afterreading here all the time I started wondering if I was getting average mpg for my boat/engines. We did start pounding then I put the tabs down to smooth it out. I guess thats when I started to lose economy.
Man I cant wait to win the lottery so I can get some 4 stroke or HDPIs

Grady White 242GT Offshore http://members.fishingworks.com/E150/

Kerry · 07-12-2003, 05:33 PM

Put another way that's around 2.7 litres to the nautical mile, that's reasonable.

Cheers, Kerry.

I never get lost, everybody tells me where to go!

Spooled · 07-12-2003, 07:34 PM

1992 Yamaha's 200 on 25 Grady Dolphin Average 1.1 MPG

My Turn · 07-12-2003, 08:14 PM

I had a 97 Grady Islander (sold 2 weeks ago) with twin 200 (carbed). Best I saw in calm water (trimmed out) was 1.7 to 1.8 mpg on the yamaha fuel management, in rough water with lots of tab 1.1 to 1.2 mpg was typical, so your numbers of 1.5 or so are actually pretty good.