What's Your Fuel Economy?

Will Lankston · 10 April 2007, 14:55

Roughly how many litres do use per hour at cruise speed?

qcamel · 10 April 2007, 15:10

anywhere between 1.2 and 2.7 depending on how much fun I am having

Nasher · 10 April 2007, 15:23

I average on a trip anywhere between 1.3l/Naut Mile and 2.1l/Naut Mile depending on lots of things. Its probably loads more for short periods.

The big guzzler on my set up appears to be If I have to do a lot of milage at displacement speed.
But also.
How much Fun I'm having.
If I'm towing a ringo.
How much weight I'm carrying.
Sea State.
Etc
Etc.

Some examples

All approx from memory.

Return trip Northney marina North Hayling to The Folly IOW.
Down through Chichester Harbour at 6 – 8 knots.
Cross the Solent to Cowes at ave 25 to 30 knots.
Up river to the folly at 6 knots
Back the same way.
44 nm and 87l of unleaded 1.9l/nm

Return trip Portsmouth Camber to The Folly IOW.
Short distance through Portsmouth Harbour at 6 knots.
Cross the Solent to Cowes at ave 25 to 30 knots.
Up river to the folly at 6 knots
Back the same way.
20 nm and 32l of unleaded 1.6l/nm

Return trip Hayling Island Ferry Inn to Cowes Town Quay IOW.
Short distance through Langstone harbour at 6 knots
Cross the Solent to Cowes at ave 25 to 30 knots.
With bursts of higher speed.
Short distance to Town quay at 6 knots.
Back same way
26 nm and 39l of unleaded 1.5l/nm

Towing ringos around in Devon
Too scared to work it out.

Nasher.

Nos4r2 · 10 April 2007, 15:24

Quote:

Originally Posted by qcamel

anywhere between 1.2 and 2.7 depending on how much fun I am having

Litres per hour?!

Depends on weather and speed-between 10 and 15 litres per hour cruising-going up to about 23/24 when I'm feeling psychotic

Nauti Buoy · 10 April 2007, 15:30

At 30-34 knots 1 litre per mile per engine

35-44 knots about 1.2l per mile/per engine

45-56 knots, 2.5 litres per mile per engine

Natually when the misses is on board 20 to 55 knots it uses about 1 litre per mile

codprawn · 10 April 2007, 15:31

Quote:

Originally Posted by Nos4r2

Litres per hour?!

Depends on weather and speed-between 10 and 15 litres per hour cruising-going up to about 23/24 when I'm feeling psychotic

Gulp I have seen about 85 on mine - cruising is a lot better though!!!

qcamel · 10 April 2007, 15:33

Quote:

Originally Posted by Nos4r2

Litres per hour?!

Depends on weather and speed-between 10 and 15 litres per hour cruising-going up to about 23/24 when I'm feeling psychotic

My mistake, meant per NM, although per hour would be less painful on the wallet

alystra · 10 April 2007, 16:13

Litres per Mile!!!

Can't tell you how much better all that makes me feel. Here was I thinking I was hard done to at 1.6 Miles per Litre at cruising speed (23knts).

Will Lankston · 10 April 2007, 17:24

These are the numbers I was estimating....Looking at probably a 5.3 length with a 90hp so I am hoping for around the 1.6l per nm mark

nik · 10 April 2007, 18:28

0.7 litre per nauticle mile doing 25-35 knots using the 1.7 litre mercruiser diesel in a 6.5 metre rib.

Nick.

JABS · 10 April 2007, 20:19

We count on 0.75 litre per nautical mile with a 90 four stroke on a Ribcraft 585.

With two up, it is less, probably significantly.

But it is worth it!

borat · 10 April 2007, 21:54

5 miles to the gallon with an average speed of 20 knots.
cheers
pete

Searider · 10 April 2007, 22:49

Will,

My 5.4 Searider with a Mariner 90hp 2 stroke did a bit better than a litre per mile. On a cruise in company we used less fuel than a 585 Ribcraft with a 4 stroke Mercury 90hp.

alystra · 10 April 2007, 22:55

Quote:

Originally Posted by Searider

Will,

My 5.4 Searider with a Mariner 90hp 2 stroke did a bit better than a litre per mile. On a cruise in company we used less fuel than a 585 Ribcraft with a 4 stroke Mercury 90hp.

I don't want to know that.

ian parkes · 10 April 2007, 23:22

on average .5 litre per mile or better if cruising at 22-25 kts , but i don't

Searider · 11 April 2007, 21:19

Quote:

Originally Posted by alystra

I don't want to know that.

I think that the 585 was a heavy boat in comparison with the searider - which, after all, is a pretty small 5.4m.

Also the 4 stroke was on carbs and not injection and working quite hard perhaps.

Don't feel too bad!

prairie tuber · 12 April 2007, 21:31

I'm not sure how close I am to the average, but a 2006 study found that the average Canadian walks about 900 miles a year.

The study also found that Canadians drink an average of 22 gallons
of beer a year.

That means, on average, Canadians get about 41 miles per gallon.

floater · 14 April 2007, 20:42

hi

just returned from a week of Ribing in Cardigan bay with the new RIB and my fuel use was

112 litres over 4 days and 214 miles (not NM) speed was between 20 and 30 knots and at least 4 people and up to 9 for one day (averaged 22 knots not bad on a 60hp ) but 3 were small kid 2 were big kids 4 adults

Andy

fjarvis · 16 April 2007, 19:09

on a calm day with little wind / tide i can get about 70 miles out of 25 litres of petrol on a 4m RIB with 40HP E-TEC.

Stoo · 17 April 2007, 19:26

Average of about 1.5 litres per NM with an average load at a cruise speed of 32 knots. Drops considerably if I pick up the pace much. I run a 150 2 stroke, V6