Triton 351/ Verado's Fuel Consuption Reports - The Hull Truth

clover2695 · 09-13-2005, 10:32 PM

Can anyone provide fuel data on the 351 with triple Verado's giving GPH and prop size and SOG from GPS. Also when looking at MPG is that accurate considering the MPH is from the speedometer and unless you are looking at the GPS it's not that accurate.

Glen E · 09-13-2005, 10:36 PM

clover - wire your speedo to read your GPS data - there are two wires coming out the back of the speedo that hook to your gps - turn off the pitot tube in the speedo setup and it will calc all the mpg/data for you - very accurate...and so's your speed!

clover2695 · 09-13-2005, 10:53 PM

Hey Glen maybe you know the answer to this question: If I am getting 8.7 GPH per engine at 3600 rpm's doing 28 kts with 19 props what should I get if I use 21's

Glen E · 09-13-2005, 10:59 PM

Quote:

clover2695 - 9/13/2005 10:53 PM

Hey Glen maybe you know the answer to this question: If I am getting 8.7 GPH per engine at 3600 rpm's doing 28 kts with 19 props what should I get if I use 21's

I defer to Sundance kid on this one - but remember you should choose props not on midrange but ones that keep your WOT fully trimmed at 6000-6400...

clover2695 · 09-13-2005, 11:11 PM

With the price of gas I am concerned about 30 - 40 mph and fuel consumption having said that I have had my props fly out of the water at high speeds several times with the 19's.

Glen E · 09-13-2005, 11:39 PM

Quote:

clover2695 - 9/13/2005 11:11 PM

With the price of gas I am concerned about 30 - 40 mph and fuel consumption having said that I have had my props fly out of the water at high speeds several times with the 19's.

look into R\rev 4 4 blades if you have prop blow out...it's what i run and i was having the same thing off of 3 blade MIrage plus's

fishboy1 · 09-14-2005, 02:52 PM

At 4800 rpm's I am getting .95 miles per gallon. Marage 21" props Tripple 250.
That's with full load of fuel and 6 passengers. Speed on gps at that rpm is 42 mph.
At 5200 same identical conditions load pasengers etc. .58 mpg (OUCH) 45 mph
After speaking with Glen I like the 4800 better than 5200 rpm's.
Next trip i am going to keep it at 4400 hopefully still running 40 mph.
Great motors love everything about them except high RPM'S.

clover2695 · 09-14-2005, 08:07 PM

fishboy1:

What did you mean after talking with Glen did you change props? At 4350 RPM's I get 33.8 kts / 38.8 mph burning 37 GPH with 19's. Will I get better gas mileage with 21's

PS I only have 40+ hours on engines should get better mileage after 100

sundancekid · 09-14-2005, 08:15 PM

If you overprop, you will see worse fuel mileage at cruise since the motors are working much harder to spin the larger pitch wheels. First thing I would do for max performance, especially on a high perf triple engine rig, is check the mounting heights of the motors. This is imperative to proper economy and efficiency. I remounted some 250s on a 32 Whaler and gained .2 MPG at cruise without having to change props or anything, also picked up 2 mph on the top end. While running at cruise, peer over the transom and see where the cavitation plates are in relationship to the water. The plates should be above the water on both sides, no water should be passing over them. If this is not the case, move the motors up a hole or two, depending on how much setback you have. After you do this, then check your WOT RPMs and see if props need to be changed. I wouldn't want those motors spinning any less than 5900 FULLY loaded. What are your current WOT RPMs? In order to insure that you are getting the proper readings, run the boat in calm water and trim the motors up until you feel the props start to break loose (you should feel a decrease in speed). Then, trim back down one tap at a time until you feel the props bite again (a little surge forward). Your RPMs here are your max RPMs and a baseline for deciding which props to use. This post is also directed at anyone who reads it, 9 times out of 10, manufacturers do not rig outboards for maximum efficiency and in today's times, you need to get every bit of economy outof your rig that you can!

clover2695 · 09-15-2005, 08:54 AM

I will have to get out and re-check however I was able to get 5900 - 6000 rpm's WOT in the bay with engines trimmed on 3, I did not try to trim higher at that time, I will re-test when I can and report back. I will also look at cavitation plates.

fishboy1 · 09-15-2005, 09:18 AM

I haven't changed props yet. But i am going to.