Of course fuel consumption numbers depend on a lot like sea and wind conditions, payload, current etc. It is often hard to get accurate numbers for comparison. With half fuel, and light load, when we ran Manta 44 hull no. 10 from the launch to the marina, with a pair of Volvo 225hp D4 engines, it was burning 5.28 gal/hr per engine on the Volvo flow meter, at 2600 rpm doing 16.4. I have an actual picture of the instruments if anyone is interested. At displacement speeds of 7-8 knots the best we have seen is 2 gal per hour.