Fuel economy question

[Daintreeboy]

Anybody know where to find some information on expected/average type fuel economies for motors if such a thing exists? I just test drove the new Mercury 60 HP that's repowering my boat and got around 11 L/hr at approx 19-20 knots. Still needs a lift and re-test with props but was interested to know how this is shaping up. Current prop is a 4 blade spitfire.
Boat is an old Timber Hartley around 16 foot.

[Noelm]

boatpoint had some old articles about different HP engine tests, might be something there, a 60 should be getting around 6-8L per hour at 4,000 RPM if its setup right, do you know your max RPM as it is?

[docaster]

Anybody know where to find some information on expected/average type fuel economies for motors if such a thing exists? I just test drove the new Mercury 60 HP that's repowering my boat and got around 11 L/hr at approx 19-20 knots. Still needs a lift and re-test with props but was interested to know how this is shaping up. Current prop is a 4 blade spitfire.
Boat is an old Timber Hartley around 16 foot.

Would you be using a bigfoot. 60 seems a bit small

http://www.########.com/engine-review/Mercury

[docaster]

Try boat test
The link won't copy properly

[Daintreeboy]

On that test it did about 6100 at WOT. At around 4000 rpm it was around 8L/h but I can't remember exactly. I should be able to launch again today and will record the changes more accurately.

[Daintreeboy]

Latest test has it faster and better economy. Just clocked it at 4300 rpm and 10.2 L/h. Speed was about 20.5 knots so pretty happy with that. Top end speed the same. This is with it lifted plus the standard three blade alloy prop, 13 inch pitch.

[chris69]

Hi Daintreeboy if its got the cab and forward steer i think you would have to be happy with those revs and speed and new motor so still tight.

[SUPERDAFF]

It's perhaps not so much an issue about litres per hour as it is about kilometres per litre.

At the end of the day, the only relevant figure is how much fuel you used to get from point A to point B.

For example, 80 litres per hour at 40 knots is exactly the same fuel consumption as 40 litres per hour at 20 knots.

(And therein also is a tip on how to keep engine hours down).

The Yamaha web site has some typical comparos of its engines on various relatively current models - well worth a look.

Note that the figures can quite easily be bettered in real life. That's because, and much to its credit, Yamaha does the right thing by running them all with the nose trimmed right down to make for easier comparisons




Anybody know where to find some information on expected/average type fuel economies for motors if such a thing exists? I just test drove the new Mercury 60 HP that's repowering my boat and got around 11 L/hr at approx 19-20 knots. Still needs a lift and re-test with props but was interested to know how this is shaping up. Current prop is a 4 blade spitfire.
Boat is an old Timber Hartley around 16 foot.

[Haji-Baba]

Re: Fuel usage.

Motor, Yamaha F.cet 60 4 stroke. @ 81 hours total usage.

Date of test Monday (3- 4 pm approx.) 28 Dec. 09.


Bongaree Boat ramp to Mission beach.

Test boat 445c. Haines in very good condition.

Approximate load of boat and gear 815 kg. , normal fishing, safety gear, 25 l of fuel.

Prop, 11 1/8 x 13g. (since changed to smaller prop.)

Weather good probably 10 knots. Tide full, little or no run.

Test exactly I hour, total distance from boat instruments 23 nautical miles non stop. G.P.S. 23.6 NM.

4200 rpm, 22-24 mph from boat instruments, G.P.S. showed 23.7 mph.

Total unleaded fuel, exactly, 10.88 litres.

These are exact figures non stop for exactly 1 hour with a couple of loops back at the ramp to soak up the last few minutes.

Have fun Haji-Baba.