Worst fuel usage from new 250 to 300hp motors

[goona]

Hi All,

Wondering what is the worst fuel useage recorded for a motor in the 250 to 300 horse power range. It has to be a motor that is no more than 2 years old.

Regards

Goona.

[Spaniard_King]

He got under ya skin didn't he :)

[goona]

Well its the old thing mate. 6 years ago he said buy a Johnson instead of a Yamaha. Wishing I didn't do that now as the Johno is a disprin whilst my mates identical 15hp but in a yamie is like brand new and he treats it like Sh_t. Shouldn't have taken that advise. I think there are a lot of variables in the fuel useage such as weight, how it is driven, conditions etc so just seeing who gets what.

[ozlongboarder]

145lts/hr at 41.6knots. 3100 Noosacat, twin 225hp Optimax 2003 models.

Not in your Hp or age range though ;)

[thelump]

Haines 680 i went out in on sunday was sitting on 4500rpm doing 28knots and drinking 49lph. Suzuki 250 2010 model. Fuel flow was a bit all over the shop though?

[Captain Seaweed]

Noble 7.5m centre cab - 2011 yamaha 300hp -1L/km averaging 4500rpm at cruise

[nelton87]

Goona,

I did some tests with the Guys from Suzuki on several vessels and you can download the results direct from there website,
www.hainessuzukimarine.com.au
If you select the Outboard size and down the bottom of the 300's and the 250's you will find two local vessels from Brisbane used in the Test.
I can verify that I have witnessed the same tests on other vessels and the information comes straight from the ECU onto the Garmin GMI 10 screens and we have verified consumption to be exactly or extremly close to when fueling the vessels
Cheers
Nelton

[Muddy Toes]

2011 Yamaha F300B on a 24ft Seapro.
1L/KM @ 4200rpm-4600rpm cruising
125L/H @ WOT for about 42knots.

[Bull]

260hp MPI Mercruiser Seacore Bravo 5000 rpm 72L/H WOT about 35 knots
42L/H @4000 rpm 25 > 27 Knots 1L/KM or just a lil better

[Smithy]

It would have to be a Verado. They seem to have an aura of excessive fuel consumption about them.

[chop duster]

verado's only chew the juice above 4500rpm. below that they are on par with most other 4 strokes. flat out our 250 verado chews 110L/H

think it is something like 2500rpm = 25L/H, 3500 = 35L/H

[Mister]

A hell of a lot more than many want you to believe :)

[wags on the water]

I don't know about you blokes, but I was worried about 76l/hr flat stick with a 200 Opti - you can have your 250's and above..

[Donkeyzmilk]

this thread makes me feel good i got a 115,...some of those numbers are plain scary.

i promise to never worry about fuel usage again haha, but i bet they are some damn nice boats you blokes are driving!!

[Zippidy]

Makes me glad I've got my old 70hp on the back. Uses about 22L/H at 29 Knotts.

[Salad Fingers]

ya gotta pay to play i guess.. im happy with my 40ltr/hr flat chat with my 140 after seeing some of these figures tho!

[WalrusLike]

The thing is that I fool around with trim trying to gain a percentage point of fuel economy, and then a little while later think 'maybe I should take a run up that other channel just for fun'.

In the first 200 meters I probably use more than I gained on the way out..... odd how the mind works.

[wirlybird]

you may as well have an inboard with that usage and you have the option to convert to gas LPG

[ozbee]

the biggest mistake people make is speed pitch down lose 5 or 6 nots top end and you will pull far better fuel consumption in all weather conditions . i went from a250 etec to a 300 zuk and saved around 40 litres in 300litres trip . pitched down from a 18.5 x 16 to a 17x 16 . lost around 6 knots at wot but at cruise 1.3 klm to the litre which is far better than my friend who has a 250 yamaha on the same hull who at best pull 1 klm to the litre. fair dinkuim reef fishers carry so much more weight in gear and speed is set by sea conditions so pitching down is no big deal to do.

[chop duster]

gas on a boat? no thanks. stern drive? no thanks. Engine hatch? not thanks...
Go for a ride on a boat running a 6 cylinder verado, they are pretty special, i have been in a few boats and nothing compares. The extra fuel usage at top end RPM's are worth it. Most boats will more than likely have a cruise rpm under 4500 rpm anyways.
Our other boat chews about 100 L/H at 16 knots (twin diesels) so 110 at 45+ knots doesn't bother me

[eugah]

I have a 2010 250 Opri and WOT it sucks 85l/h @ 36 knots, back it off to around 30 knots and it drops back to under 60 l/h. In my opinion if your concerned about the fuel comsumption get something smaller.

[goona]

Ozbee Thanks for your advise. Been thinking of getting smaller prop as mine only revs out to 5400rpm WOT. When loaded it is even less. I would be stoked to get 1.3klm per litre. I am currently getting 1klm per litre from my 225 Honda on the 7.4m Pacific sport fish.

[wirlybird]

gas on a boat? no thanks. stern drive? no thanks. Engine hatch? not thanks...
Go for a ride on a boat running a 6 cylinder verado, they are pretty special, i have been in a few boats and nothing compares. The extra fuel usage at top end RPM's are worth it. Most boats will more than likely have a cruise rpm under 4500 rpm anyways.
Our other boat chews about 100 L/H at 16 knots (twin diesels) so 110 at 45+ knots doesn't bother me

Each to their own plenty of boats running gas these days and pull good numbers and its no more dangerous than fuel if installed properly. A bog stock 350 MPI will have better economy than a yammie 350 outboard and the other two "?" are a personal preference not really on topic. i prefer not to fish around an outboard/s and the engine hatch is a good seat :)

A diesel is an inboard still isnt it????

[chop duster]

your right wirly 'each to their own' :) just not a fan of sterndrives and gas on boats. sorry to get off topic.

Im finding the rpm to fuel figures interesting... Hp or torque to fuel burn would be even better but as far as i can tell is only ever available for diesel engines...

[rhodesey]

Yeah big boats big outboards my 250 Verado loves a drink on full noise around 106 litres an hour around 36 knts 6100rpm. Not that I go there to often. Try to stay around 4300 to 4500 rpm 25 knts around 45 litres an hour. Normaly get around 1klm to the litre for a trip. Four persons on board beer ice and between 300 to 400 litres of fuel.
Cheers Mark

[wirlybird]

i was on a shark cat 23 with two 275 verados and i was astonished at the lack of fuel economy. Also there is a guy in cairns that has 1 275 verado on his formula and he gets 55 LPH BUT the prop makes a huge difference. He had a 19 pitch prop getting 75LPH then down to a 17 pitch prop achieved the 55 LPH

Diesel is still the far better engine for fuel economy especially the new Cummings direct injected engines.

[Drew70]

Big heavy cats take fuel consumption to another level. Ive had numerous cats over the years on outboards and my current 28 Sharkcat has been a real eye opener comparing different outboards. The boat is heavy, pushing 4.5 tonne loaded with fuel / gear / water and takes horsepower to cruise as all bigger boats do.

A few years ago decided to upgrade the Saltwater 200 yammies as fuel was high on longer trips limiting range and fumes werent pleasant being sucked into the cab while trolling.

Decision was made to put a pair 2007 Ex Water Police Verado 250's on the back with plenty of promises of how good they would be. The Verado's were whisper quiet and the power steering and flyby wire controls/data screens were fanatastic. However open the throttles and watch the fuel gauges plummet. At 4100 revs which was optimal fuel efficiency (0.4km/L) doing 20 knots at 95+ litres per hour combined. Revs outside the range really pulled the efficiency numbers down even further. Top speed was 36 knots at 230 L/hr. Various props with pitches / cupping / 3,4 blades were tried over a few months with fuel reductions of around 10 % which was nothing special in the overall scheme.

April this year Verados were replaced with a pair 2012 yammie 250's (4.2L versions) with the first noticeable improvment of removing 130 kgs off the transom (Verados are heavy). Optimal cruise now begins at 3100 revs doing 22 knots at 51 L/hr (0.75 km/L) and fuel effeincy stays the same right through to 32 knots and doesnt drop dramatically through to 35 knots. Max speed is now if you can hang on at 45 knots.

To be fair on the Verados they were Gen 1 units and Gen 2 models have been reported to be around 10 % better on fuel however I would be very careful putting them on a heavy boat that carries load.

Have around 75 hours on the yammies now at cant be happier, their big displacement blocks allow lower revs at cruise with plenty of torque which translates into good fuel effeincy when pushing weight. Service parts on yammies are very reasonable now as the Verado parts were unbelievable, $25 spark plugs, anode kit $180/motor and super expensive specialist oil.

Many big HP outboards are not running optimal props causing poor fuel efficiency numbers. A lot of research over 12 months trying to improve the fuel on the verado lead me to Prop Slip Calculators. These tools are fantastic to look at your current prop setup and punch in differnet prop pitches to reduce prop slip in the water which is the biggest cause of fuel use. These calculators are easily google searched and provide a great insight to your setup.

On a final note on big outboards make sure your prop size allows revs through to the top of the motor specs. WOT revs below where they should be puts load on the motor and doesnt allow optimal rev range to be achieved which burns fuel. Pitch isnt the only number on props the cupping has a massive influence on performance. Ken at Propgods.com in the US provides excellent advice if you need it as does Steve at Solas here.

Cheers Drew

[chop duster]

Odd to pick up 9 knots top end that's for sure. Do you think it was the weight change?

[pointertri]

I have a 300hp Yamaha on a 773 Haines which will do 1.3 km/l at 24 knots to 1.1 km/l at 29 knots with a less than half a tank of fuel. A full load of fuel or a heavy load will take it down to 1.2 km/land 1 km/l at similar speeds.

I have been really happy with the motor. Acceleration is impressive.

[NTMID8]

Wow big boats = big fuel bills! My 4.7m sig with its 93 60hp evinrude gets an avg of 2.2 - 2.5 km/l travelling at 24knts.

[Finnatical]

I have a 2010 KC3000 with 300 Suzukis (non Lean Burn models) with no anti-foul. In usual 10-15kt conditions with a normal load for fishing (400-500 litres of fuel 3-4 people and gear etc) at 3500rpm it is doing 26/27 kts for 55 l/hr and at 4000rpm 31/32kts for 70 l/hr. Flat out is around 180 l/hr for around 48-50kts, but top speed is more affected by load obviously. I hear the new Lean Burn models are doing a little better than these figures.

[goona]

Hi Drew,

Thanks for a very comprehensive write up. Just goes to show about the correct prop as I am pretty sure mine is to large and affecting the fueel ecconomy. I will be getting a smaller one and hopefully with the better economy will come more range as well which will mean more exploring out at the Swains on our annual trips

[goona]

I have a 2010 KC3000 with 300 Suzukis (non Lean Burn models) with no anti-foul. In usual 10-15kt conditions with a normal load for fishing (400-500 litres of fuel 3-4 people and gear etc) at 3500rpm it is doing 26/27 kts for 55 l/hr and at 4000rpm 31/32kts for 70 l/hr. Flat out is around 180 l/hr for around 48-50kts, but top speed is more affected by load obviously. I hear the new Lean Burn models are doing a little better than these figures.


Hi Finatical,
Is that the fuel useage for both motors?

Goona

[ozlongboarder]

Here are some test numbers from the Haines website.
http://www.thehainesgroup.com/new/_inc/doc_download.aspx?siteid=8&did=76

I'm going to call Solas and try some different props on my Optis. See if I can improve my economy.

[Finnatical]

Hey Goona,

Yes that is for both motors. The numbers are taken from the digital gauges. I am quite happy with the economy for what is a pretty big block of flats to be pushing along at quite good speeds. Goes someway to confirming the argument that bigger motors working easier will be more efficient.

Cheers,

[goona]

Hi Finatical,

Thats fantastic economy and about the same as my single 225 unit. II think I have definately got to look at a new prop by the sounds of things

Regards

Goona

[seahound]

running twin lean burn (2012) 300hp suzis on a 10m mono. getting similar figures as finnatical. sister ships with twin 250 yammie & suzi using average 15% more at 2500 to 5500rpm. was a surprising difference.

doesnt get much better for big hp on bigger boats at speeds over 20-odd knots.

know of a few tubs with twin 200 verados on 8.5m hull & WOT fuel burn same as the twin 300 suzis - also similar from around 4000 rpm. the verados are good at lower rpm but do chew its once the supercharger kicks in. most use will be 4500rpm & under if offshore. once the super kicks in, they go hard...

[TimiBoy]

My 250 Verado (when I had one) was on a par with other donks up to about 4500 revs, burrning around 45 litres an hour. It pushed up to 107 per hour at 6200 revs pushing a Cruisecraft 685. Was it sexy? You bet, but next outboard will be a Yammy - the V-rod was hard to sell. They have updated the Verado though, mine was a 2005 model, and I'm sure they've improved on fuel. everything else was perfect, so a hard donk to improve, imo.