fuel consumption

[Rickwaines]

I just came back from my first trip in my Hurricane 530 with a Mercury Jet80.
I had a fantastic time but was pretty surprised at the terrible fuel economy. I probably shouldn't have been given the engine is a 4 cylinder 2 stroke 115 hp head which translated in 80 hp at the head. Fuel economy is not it's strong suit, clearly.

I managed to get about 2 litres to the Nautical mile.

What I am wondering, is, what fuel consumption I might expect (A broad range is acceptable) if I were to switch to a 4 cycle 80 hp prop engine.

Thank you in advance, Rick

[MatFromPoland]

2 liters per 1,8 km it is 0,9 km per 1 liter

I have HIGHFIELD OM540DL with EVINRUDE 115 HO + Evinrude Rebel 19" prop
Usually till 3800 - 4200 RPM (which gives me about 45 km/hr - 50 km/hr) I see very often fuel consumption like:

2 km per 1 liter which is 2 times better
sometimes (wind waves)
1,8 km per 1 liter

It is moder 2T but when compare to HONDA BF100 (which is 4T) with the same boat (Steve from SeaSwift send me some details) I have the same consumption at higher speed.

5 people on board (about 300 kg), 2 batteries, 2 anchors, 100l of fuel, 20 l spare fuel, snorkel equipment for 5 people.

Boat weight with fuel and all items about 900 kg.
Passengers and bags - maybe 320

WOT is 5500 rpm

[Poly]

Rick, as a very broad rule of thumb mostly people with 6+ m boats here reckon on cruising somewhere around 1 NM / L obviously how it's driven, your speed, the weather/waves, the amount of kit you carry and the appropriateness of the particular engine to the hull all make a difference. Jets are less efficient but if you were getting less than 0.7 NM/L with a traditional outboard then I'd be disappointed. If you were getting more that 1.5 you are very well, until you get down to very small boats.

The guide used to be 4 stroke was 20-25% better fuel economy than 2 stroke but the difference isn't constant at all speeds.

[Xk59D]

if it helps my old mariner 4 stroke 100hp on 5.6m rib got 0.7lpnm

that is some serious fuel consumption you have there.

my 6.8 with 200 4 stroke is way way better than that.

[jambo]

Originally Posted by Xk59D

if it helps my old mariner 4 stroke 100hp on 5.6m rib got 0.7lpnm

that is some serious fuel consumption you have there.

my 6.8 with 200 4 stroke is way way better than that.

Come on Paul don't keep us in suspense what do yo get with your new rig?


Sent from my iPhone using RIB Net

[Xk59D]

The 6.8 is 0.8l per statute mile with the 200

[tom's]

Originally Posted by Xk59D

The 6.8 is 0.8l per statute mile with the 200

4 or 6 cylinders the df 200?

[Xk59D]

6 cylinder 200df

[jambo]

Originally Posted by Xk59D

The 6.8 is 0.8l per statute mile with the 200

That's excellent bet you see the difference in your pocket

[willk]

Originally Posted by Xk59D

if it helps my old mariner 4 stroke 100hp on 5.6m rib got 0.7lpnm ...... my 6.8 with 200 4 stroke is way way better than that.

Originally Posted by Xk59D

The 6.8 is 0.8l per statute mile with the 200

So when you say "way way better", you kinda mean "worse"?

[Xk59D]

No, it is way better than op

[willk]

Originally Posted by Xk59D

No, it is way better than op

Well yes, the Queen Mary got better mileage than the OP

[mick]

Originally Posted by willk

Well yes, the Queen Mary got better mileage than the OP

Glad I'm not filling the boat my lads on 2 hrs to put 14,000 L in and it can burn a 1,000 L per hour 😳😳

[kerlstone]

[QUOTE=Xk59D;724485]if it helps my old mariner 4 stroke 100hp on 5.6m rib got 0.7lpnm

Dont you mean 0.7nm per lt ?
Gerry.

[Xk59D]

No I do not, sipped fuel my old boat.

The above was 20knots which is where it seemed happy but upto 25knots it was still under 1lpnm.

I use statute now as I just say worst case 1 litre per mile with the ribcraft and when looking on google maps for trips it is just easier.

[HUMBER P4VWL]

Well dragging our tubes, 3up and carrying 200litres in a Humber 6.3m with 175hp Opti, in roughish sea over 85miles we are at about 1.4L pm.

2up and 100litres in calm sea, cruising speed, probably just over 1L pm

[Rickwaines]

such a great site!

[HDAV]

The economy on the jet OB is terrible why are you running a jet? When was the pump last serviced? Could be pump is partly to blame.

[Rickwaines]

Originally Posted by HDAV

The economy on the jet OB is terrible why are you running a jet? When was the pump last serviced? Could be pump is partly to blame.

I agree, which was the motivation for the post in the first place. The rib came with the jet outboard, I wouldn't have otherwise bought a jet. Certainly not now after having used one for a few hours. I did have the engine inspected and serviced. The impeller that is responsible for pulling the water was in good shape apparently so I'm not sure that this particular engine would be capable of better performance. I am thinking of replacing the leg with a prop leg. That will improve the fuel consumption somewhat I would think and certainly it would help with handling when docking. A new engine would be my first choice but that expense might need to wait a year or so.

[HDAV]

Depending on the cost of a prop leg could be a good option.

If it's all been checked out then that's the probably as good as it will get...... Apart from the fuel burn does the motor move the boat well?