tophatyachts.com

Since there has been some discussion about fuel usage, here is an interesting calculator I just came across:

https://www.mercurymarine.com/en-gb/au/fuel-savings-calculator

I know it does not compare petrol to diesel (sigh) but I found it useful since I had been wondering at the difference between 4 and 2 strokes.

troppo

Thats a handy link.
And it mirrors nearly exactly the fuel consumption figures I am getting on my Tohatsu 8hp 2st, which uses around 1.5lts of fuel per hour at around 4.5kts.
I always allow 2lts per hour of intended motoring to work out my range & that allows for a pretty big safety margin, for maybe adverse current, chop, headwinds etc.
cheers