Best Boat for European Waterways

[pheran]

Sorry. Interesting figures here but I can't see where you get your claimed fuel economy. The idea here was to use one engine run at higher revs to a) maintain your chosen cruising speed and b) give that engine a little more work to do to try and avoid the down-side of low speed running. Others experience has been that one engine or two, doesn't make any significant difference to fuel consumption. Your figures too, seem to confirm this

1500 revs x 1 engine = 7 knots @ 3 MPG.
1000 revs x 2 Engines = 6.8 Knots @ 2.8 MPG

ie if you want to travel at around 7 kts you are going to get around 3MPG. Any closer analysis would seem to smack of spurious accuracy. And then there are the other downside effects of single-engine running to be taken into account.

 

[jcmmarine]

Being retired we are:
a. In no rush to go anywhere.
b. Trying to keep fuel costs down.
Single engine running means we can enjoy the scenery with minimal engine noise and also greatly extend the time between trying to find somewhere to fuel (difficult to find inland in France).
It also puts more load on the engine.

 

[jcmmarine]

Just realised why you questioned. Missprint. Should be 5.8 not 6.8, Would have realised if worked out the TPK. One finger typing trouble.

2 x 1500 @ 8.5 TPK = 176
1 x 1500 @ 7 TPK = 214
2 x 1000 @ 5.8 TPK = 172
1 x 1000 @ 4.8 TPK = 208

What is still the same is my aim is fuel economy whist keeping reasonable load on the engine.