I dont think it works like that though. First, you only get any meaningful info on an extended passage/use. saying you get 5000 miles a litre when you are in fact drifiting down river is a bit pointless- you might just as well be using 5000 litres a mile going the other way.
Next, you are out for pleasure. Sure, that doesnt mean you drive everywhere full throttle.
It does mean that one day, the sea is flat, there is no hurry, and you meander along enjoying the coast. Another day, maybe the weather will close in later, and you push it a bit to get home in time. In both cases the goal isnt fuel savings-something else over rides that.
You can feel when the boat is running well for the conditions, that is a good indicator.
One 500 mile cruise we did about 2.25 lpm-sea was great, easy boating. Another 500 mile cruise we did about 2.5lpm-and we certainly went slower, but that was the sea conditions.
I cant see how peering at a fuel readout would have changed anything, other than ruin the day !
Originally Posted by gjgm
I don't agree; it takes surprisingly very little boat outdrive trim/ throttle adjustment to make a fairly big difference in mpg/ litres per nM as indicated by the fuel computer. If I want to travel at WOT I will if it's comfortabe. Otherwise, if travelling 30 mph+ at 2.6 or 3 mpg in no rush to get somewhere then I'd probably choose 3.0 mpg !
Last edited by GrahamHR; 03-05-12 at 07:13.
My reason for fitting a fuel meter was 'like to know'.
I simply wanted to be able to go at most economical speed and trim possible at any time. Thus not optimizing every minute since all the mentioned parameters must be taken into account, but by far most of the cruising was done at the sweet point.
Hate to burn too much fuel by coincidence...