30% improved fuel economy from new DF115B 😁

[Moonlighter]

OK upfront, its not a bassboat and isnt driven at WOT all the time….. its a saltwater boat, cuddy cab, heavy duty plate aluminium 18footer, with an 18 degree V all the way to the transom. Great bay and inshore boat, and offshore on good days, I have had it out 40 miles to the Great Barrier Reef off central Queensland.

I have just had a new 2022 DF115B installed. New engine, harness, binnacle, and SMG4 digital gauge. All networked via NMEA2000 to my Simrad GO7 xse and Lowrance HDS7 Gen3 and Elite FS9 displays. Kept the Suzuki 14 x 20 SS prop from the old engine as it was perfectly matched, and I had it refurbished only 18 months ago so in great condition.

Replaces a DF115 2010 model that has run flawlessly ….. It was however 13 years old, and I got a very good changeover price from my local Suzuki dealer who Ive known for many years.

So took her out on Tuesday on Moreton Bay off Brisbane, Queensland, Australia, to do the running in process, and hopefully catch a few fish.

Put over 5 hours on her. Ran flawlessly. Stayed under 4000rpm for the first 1.5hrs and then around 4-4500 for another hour. Opened her up a bit to max out 5600, but kept below WOT.

Trip distance recorded on the SMG4 was 123kms and showed 46 L of fuel used. Trip average 2.7 km/litre.Thats 6.35mpg.

The 2010 DF115 average was just under 2.1km/L.

My dealer had predicted up to 30% better fuel use and yep, he was spot on.

Sweet spot around 41-4200rpm, 22 knots, which saw 3.1km/L!! Thats 7.3mpg…..

I could see as the engine hours increased the fuel economy was gradually improving as she loosened up. Not sure its going to get much better from here but we shall see!

And yes, we did catch a few mackerel. We call them School mackerel here. These were decent sized models, about 80cm. Chunky and very tasty on the BBQ with some macadamia oil and lemon pepper.

photo of the boat on the water taken a few years ago with the old Zuke still fitted. Need to get some photos on the water with the new B model on it.

[Tim Kelly]

Amazing they can squeeze so much more economy out of an already efficient motor!

[Moonlighter]

Amazing they can squeeze so much more economy out of an already efficient motor!

true!

In this case I went from the original DF115 series and jumped the A series that followed from 2012-2021 and straight to the B series.

The A series was about 15-20% better on fuel than my original series, and the new B series a further 10%.

So the end result for me was the 30% gain.

Under the cowl you wouldn’t recognise the B series engine as the same as either the original or A series. Although the same cubic capacity, its a completely new block, head and electronics.