Fuel consumption advise

[Andy4k6]

Hi,

I am looking for some basic advise on fuel consumption.

I live in the UK and have been looking for my first boat but have found a bit of a barn find, it's what looks like a Stingray 541ZP fitted with a Yamaha 130hp V4 outboard.

I am looking into buying this boat from the owner as judging by the dust on the cover it's not been used in 2-3 years but is in reasonable condition.

My question / concern is how much fuel this will use, i intend on using the boat with friends and family for pottering round and some skiing and towing toys.

On an average day trip (4-6 hours) how many Litres (or UK gallons) am i likely to need / use?

I was originally looking for a 15-16ft boat with a 80hp outboard, how much more fuel am i likely to use with the 130hp 17'9ft stingray? I am guessing there would not be too much difference as i would be pushing the engine less to get the same speed / power?

I know this is a very difficult thing to measure but a ball park figure on other peoples experience would be greatly appreciated as I'm quite new to this other than many years fishing from my dads fishing boat.

Many thanks

Andy

 

[Splat]

Re: Fuel consumption advise

I've heard a very basic ruleof thumb is 10% of your h.p. in gallons in one hour.

So if you have a 95h.p. you would burn approx 9.5gallons per hour crusing.

140h.p. would be approx 14.0 gallons per hour.

Like I said its a very rough guess but should give you some idea.

Bill

 

[Splat]

Re: Fuel consumption advise

BTW 1 gallon is 3.78 litres.
Bill

 

[JoLin]

Re: Fuel consumption advise

I've heard a very basic ruleof thumb is 10% of your h.p. in gallons in one hour.

So if you have a 95h.p. you would burn approx 9.5gallons per hour crusing.

140h.p. would be approx 14.0 gallons per hour.

Like I said its a very rough guess but should give you some idea.

Bill

Actually, that rule of thumb applies to consumption at wide open throttle...

Cruising should be significantly less. Sorry I can't provide a direct basis for comparison, but my 21' Pro-Line with 175 Johnson OB consumed less than 10 U.S. gph at normal cruise (4000 RPM). Imperial gallons are larger than US, if I recall correctly.

Hopefully others running rigs similar to yours can provide a better estimate.

 

[Silvertip]

Re: Fuel consumption advise

The 10% of horsepower in gallons/hour is a very valid number but at wide open throttle as indicated. Therefore the 130 HP engine would consume about 13 g/hr at WOT. Cruising assumes about 1/2 - 2/3 throttle and on-plane and that should result in about 7 to 9 g/hr. Fuel consumption numbers at anything less than WOT are hard to predict since wind, water, boat, load and other conditions affect that number.

 

[45Auto]

Re: Fuel consumption advise

Go to the Yamaha Performance Bulletins and look up a boat similar to a Stingray 541ZP (I couldn't even find a picture of one on the internet). They'll tell you exactly what you'll get:

http://www.yamaha-motor.com/outboard/products/perfbull.aspx?ls=outboard

The 130 will most likely burn between 5 and 8 GPH at best cruise (around 4 MPG), the 80 would probably be between 4 and 7 GPH (around 5 MPG).

Boattest.com also has lots of tests on outboard boats with fuel consumption data:

http://www.boattest.com/

 

[Andy4k6]

Re: Fuel consumption advise

Thanks for the advise guys,

It's looking like it's going to be an expensive trip out when i go as the boat I'm looking at holds 83L of fuel and if i was to burn that it will cost me ?97 which is about $145

However working on the above figures at 10 US GAL per hour i would only have 2 hours worth of fuel would a manufacturer really put such a small tank in the boat?

I'm also very interested in hearing from owners of similar rigs to the ones i have mentioned above as I'm seriously hoping i have got this wrong.

Many thanks

Andy

 

[Andy4k6]

Re: Fuel consumption advise

Go to the Yamaha Performance Bulletins and look up a boat similar to a Stingray 541ZP (I couldn't even find a picture of one on the internet). They'll tell you exactly what you'll get:

http://www.boattest.com/

Thanks I'll get looking

As for the 541ZP it's the same as a 551ZP however it was only made for 1 year (1992) much less common and could be used with upto a 135 hp outboard instead of only a 120 like the 551.

Andy

Boat detail
http://www.stingrayboats.com/products/catalogs/1992/5.pdf

Full year brochure
http://www.stingrayboats.com/products/catalogs/1992/all.pdf

 

[45Auto]

Re: Fuel consumption advise

Have you seen this test on a 551 with a 90HP Honda 4 stroke? It got 7.4 MPG at a 25 MPH best cruise, which is about 3.4 GPH. The 2 stroke Yamaha's would probably use about twice that much fuel.

http://www.stingrayboats.com/products/reviews/tb6-96.html

 

[vhuevos7]

Re: Fuel consumption advise

Welcome to the wonderfull wild world of boats

 

[Andy4k6]

Re: Fuel consumption advise

Have you seen this test on a 551 with a 90HP Honda 4 stroke? It got 7.4 MPG at a 25 MPH best cruise, which is about 3.4 GPH. The 2 stroke Yamaha's would probably use about twice that much fuel.

http://www.stingrayboats.com/products/reviews/tb6-96.html

Thanks for that, makes some interesting reading, How does a 4 stroke compare with a 2 stroke in terms of fuel economy?

Many thanks

Andy

 

[CV16]

Re: Fuel consumption advise

I can say that I have a 17 Gal.(US) tank in my 16' ski boat with a 150 hp Merc on the back. I can go for a weekend on one tank of gas just pulling tubes and skiers around. I never really paid attention to gallons per hour, but pulling people around I'm at about 1/2 power, if that. Also, a 6-8 hour day at the lake doesn't mean you are running that whole time.

 

[Beefer]

Re: Fuel consumption advise

Boat detail
http://www.stingrayboats.com/products/catalogs/1992/5.pdf

Full year brochure
http://www.stingrayboats.com/products/catalogs/1992/all.pdf

Very umm.... "outstanding" young women in those brochures... Guess that's to remind us why we love boating

 

[scutly]

Re: Fuel consumption advise

as i read this thread and my 100 gallon tank sits empty, i started crunchin numbers. i got a 300 + HP big block that would burn 30 + GPH at WOT. so i figure cruisin at about 27 MPH at 3200 RPM id be burnin about 18 GPH. so 18 gallons to go 27 miles gives me 1.5 MPG at $4 per gallon on the water. so what im gettin at is it cost me around $3 PER MILE or $1.20 PER MINUTE to cruise around THAT EQUALS ABOUT A QUART MILK CONTAINER FULL OF GAS EVERY MINUTE!?!?! is there a midget in my bilge pouring gas down my carb? someone please tell me im tired and my math is wrong. :redface:

 

[QC]

Re: Fuel consumption advise

I think you'll do a little better than your numbers, scutly. Take a look at these results which may be close to yours . . . If your top speed is similar then your cruise economy should be close too.

http://www.boattest.com/boats/Boat_video.aspx?ID=1012#Test-Result

Also important to note that the 10 HP per GPH is a little pessimistic with most modern engines. This 320, burns less than 25 GPH at WOT. Your results WILL vary

 

[Andy4k6]

Re: Fuel consumption advise

I can say that I have a 17 Gal.(US) tank in my 16' ski boat with a 150 hp Merc on the back. I can go for a weekend on one tank of gas just pulling tubes and skiers around. I never really paid attention to gallons per hour, but pulling people around I'm at about 1/2 power, if that. Also, a 6-8 hour day at the lake doesn't mean you are running that whole time.

Well that does sound much less painful if thats the case, The main problem here in the UK is the fuel cost.

Very umm.... "outstanding" young women in those brochures... Guess that's to remind us why we love boating

If it makes you feel any better the women in that brochure are probably now in their 40's

as i read this thread and my 100 gallon tank sits empty, i started crunchin numbers. i got a 300 + HP big block that would burn 30 + GPH at WOT. so i figure cruisin at about 27 MPH at 3200 RPM id be burnin about 18 GPH. so 18 gallons to go 27 miles gives me 1.5 MPG at $4 per gallon on the water. so what im gettin at is it cost me around $3 PER MILE or $1.20 PER MINUTE to cruise around THAT EQUALS ABOUT A QUART MILK CONTAINER FULL OF GAS EVERY MINUTE!?!?! is there a midget in my bilge pouring gas down my carb? someone please tell me im tired and my math is wrong. :redface:

It could be far worse, if your only paying $4 per gallon imagine moving to the UK and paying $6.8 for a US Gal


Thanks for all the help and advise guys, please keep it coming.

Andy

 

[45Auto]

Re: Fuel consumption advise

as i read this thread and my 100 gallon tank sits empty, i started crunchin numbers. i got a 300 + HP big block that would burn 30 + GPH at WOT. so i figure cruisin at about 27 MPH at 3200 RPM id be burnin about 18 GPH. so 18 gallons to go 27 miles gives me 1.5 MPG at $4 per gallon on the water. so what im gettin at is it cost me around $3 PER MILE or $1.20 PER MINUTE to cruise around THAT EQUALS ABOUT A QUART MILK CONTAINER FULL OF GAS EVERY MINUTE!?!?! is there a midget in my bilge pouring gas down my carb? someone please tell me im tired and my math is wrong.

Only thing wrong with your math is that you're probably a little too high on your cruise GPH. It's probably around 12 GPH which would mean that you're getting about 2 MPG instead of 1.5 MPG. Just means that it's only costing you about 90 cents per minute instead of $1.20/minute.

is there a midget in my bilge pouring gas down my carb?

Nope, there's a big, heavy boat in the water creating lots of drag which requires lots of power to push it through the water. Lots of power = lots of gas .....

 

[Andy4k6]

Re: Fuel consumption advise

Well it looks like any kind of boat is going to be expensive to use, I may as well just jump in an try to buy the boat i have found in the barn and see what it's like once i own it.

Andy

 

[45Auto]

Re: Fuel consumption advise

Well it looks like any kind of boat is going to be expensive to use

If you realize that up front, you'll probably be much happier with your boating experience!

You do know that "boat" stands for "Break Out Another Thousand", don't you?

PS: The boats don't care whether you break out another thousand in dollars or euros, it's all the same to them .......

Good Luck!

 

[Philster]

Re: Fuel consumption advise

Having various fun all day with a 130 HP outboard on a boat around 18' and you'll burn up to 10-12 gallons, maybe a touch more.

Full of adults and hard throttle and you could blow through 18 in a long/hard day.

So, you could get 18 gallons to last a weekend. This jives with CV16's post.