the 300 zuk. is becoming a far better fuel miser than the collection of 250 di and fourstrokes on the market it seems in the heavier boat market in single outboard configurations .
on the last trip we had a companion 7 mtr fisher with a 225 optimax .mine is a 300 zuk on a 680 patriot . previous trip we had the same boat as mine but with a 250 fourstroke. .
on the same trip my 250 etec would use 320 litres of fuel
the 300 zuk came in at 240 litres of fuel
the opti max came in at 330 ltrs of fuel
yamaha 250 came in avg around 270 litres
there is a few things to consider and that is it was calmer when we went with the opti ..speed wise we sat on 30 knts rather than 25 knts which may of dropped it just out of there cruising range. they said at the end they preferred 25 knts whether the patriot cut the chop a little better or that's it cruise speed .
my 250 etec liked 25 knts though litres per klm didn't change much faster or slower. so i feel the opti is similar to the etec
it seems the four litre block of the 300 is carrying better than the range of 3 litr 225 /250 blocks for this range of size boat
all boats were filled up straight after the trip