Fuel economy question - The Hull Truth

bigrockbound · 02-24-2010, 05:14 PM

I am looking for a new ride, and found a 29cc angler with twin 250 HDPI yamahas. What do you think it would do as far as MPG?

cazador · 02-24-2010, 06:41 PM

HPDI's are rumored to be about as fuel efficient as Optis, which are about as fuel efficient as 4-strokes.
Having owned an outboard powered 30 footer, my guestimate is about 1.1 to 1.3 n.m.p.g. cruise in the sweet spot 22-26 knots @ 4000 rpm.

signmansez · 02-24-2010, 07:06 PM

My Pursuit 2870 does 1.5 to 1.7 with Yamaha 225 SS EFI's. The Angler will probably do that or a litttle better.

2stroker · 02-24-2010, 07:23 PM

I have a boat that had twin 250HPDI's on it and now has 250 four stroke Yamahas. Fuel economy is similar with a ever so slight edge to four strokes.

Capttater · 02-24-2010, 10:08 PM

Quote:

Originally Posted by cazador

HPDI's are rumored to be about as fuel efficient as Optis, which are about as fuel efficient as 4-strokes.
Having owned an outboard powered 30 footer, my guestimate is about 1.1 to 1.3 n.m.p.g. cruise in the sweet spot 22-26 knots @ 4000 rpm.

I disagree on the HPDIs. I've had Optis and 300HPDIs. HPDIs don't do the fancy economy stuff like lean mode and such. However I think he'll get better than 1.1-1.3.
I have a HEAVY Regulator 32 and got 1.6SMPG until E10 then down to .9-1.1. I'd hope he sneaks up on the 2mpg with the 250s if all is clean and running well.

Bullshipper · 02-24-2010, 10:30 PM

google yamaha. go to their performace reoprts, then deduct about 20% off the light boat result for real life expectations.

Capttater · 02-24-2010, 10:39 PM

Quote:

Originally Posted by Bullshipper

google yamaha. go to their performace reoprts, then deduct about 20% off the light boat result for real life expectations.

I just tried 1/2 hr ago. Get this.. Looks like they pulled all HPDI reports other than the 200. Even if you go to their Archive (hard to find) .. nothing on other HPDIs.. Hopefully it's temporary but I'd imagine they don't want to show how poorly their new 4 stroke motors compare.

http://www.yamaha-motor.com/outboard.../perfbull.aspx
As soon as you pick 2 stroke and 250 and up you get nothing.
Even if you pick a 200HPDI, pick a type of ALL and a brand of ALL you only get about 30 and they are all 200s and 225s.

Bullshipper · 02-25-2010, 10:52 PM

wouldnt own an hdpi or opti.
time bombs with short fuses.

Birdman · 02-25-2010, 11:13 PM

I wouldn't own an outboard, UNLESS it was a 200 HPDI.

modunlavy · 02-26-2010, 07:18 AM

Here is something that will get you "close" to the mpg...

the WOT fuel burn, on a gas engine, will be close to the total hp divided by 10. At 75% rpm of WOT, the fuel burn will be about half of what it is at WOT. If the current owner can give you "real" speeds or if you can sea trial the boat yourself, then you can get a basic idea with this formula....

Fasana · 02-26-2010, 07:29 AM

Here is a link to a study comparing different outboards and technology.

It originally appeared in the February 2004 issue of Vene Magazine.

http://www.yamaha-motor-europe.com/p...ws/article.jsp

It does an excellent job of explaining the difference between the 4s and 2s performance numbers.

marty grady 272 · 02-26-2010, 08:35 AM

I have a 272 Grady with 2 200 hp hpdi motors. I get 1.7 to 1.9 mpg. I love my hpdis

Team Balla's Steakhouse · 02-26-2010, 08:50 AM

You should able to get 2mpg.

My friend owns a '04 250HPDI w/ 1,000 hrs. Very tough motor. No Major Problems. Good on fuel.

solarfry · 02-26-2010, 09:24 AM

Fuel economy Depends on the prop, weight and boat design and can vary wildly even among identical boats.

see:

http://www.yamaha-motor.com/outboard...px?ls=outboard

The prop can make a difference as your can see below.

and.

Amazing that a change in prop can make such a difference in mileage and high end..

Gasoline with ethanol has less energy that regular gas without ethanol. Your mileage will decrease with ethanol so we can keep the corn lobby happy. My truck went from 14 mpg down to 10 on the switch to ethanol.

v70cat · 02-26-2010, 04:08 PM

I get 2.4 MPG on my 27 WC with twin Honda 225's. This is a at a 28 to 30 MPH cruise.

Based upon prop tests they get better MPG and are faster than a Yamaha 225.

Birdman · 03-06-2010, 11:16 PM

I got 2.4mpg on my 28' Scout, with 200 HPDI Yami's, cruising at 36mph.

Bullshipper · 03-07-2010, 04:02 PM

Well, I am not denying the great fuel milage, or 1000-1500 hrs typical head life.

But show me some hdpi with +5000 hours like the commercial boats are getting with 225 yami 4 strokes, and I will believe that a 2% savings in fuel economy can equal the the total fuel + motor replacement cost.

Birdman · 03-09-2010, 03:22 PM

Show me a 225 4 stroker with 5000 hours on it. [insert cricket sound here]

Bullshipper · 03-09-2010, 06:48 PM

Talk to Josh Temple Bird. The 1st of a pair of 225's went down on him with over 5100 hrs, and the twin sister is still going as I understand it.

Another other Mexican captain friend (Chapparo) had a 50 hp Merc bigfoot fall off his boat and spend 3 days under salt water before he repaired it and got it back on his panga. That one just died last year with 5223 hrs.

Both of these motors lived on mexican gas and regular motor oil their whole life, which aint the best, believe me.