"Real-World MPG on 2018 Cutwater 302 Coupe with Twin Yamaha

[northernlines]

"Hey fellow boaters! I'm in the process of purchase a 2018 Cutwater 302 Coupe with twin Yamaha 300s and finding conflicting information about its fuel consumption. The official stats say 1.3 mpg, yet there's talk of as low as 0.8 mpg on this forum, with the dealer is quoting a solid 1 mpg. Anyone here with the same model who can share their cruising mpg? Looking forward to your real-life numbers!"

 

[Journey]

I have a 2019 c302. I have used it in many different types of cruising. I have never even come close to 1.3. I consistently get .7 mpg at 25mph or 40mph doesn't seem to change much once in a great while I will get 1.0 but it is short lived. I am very disappointed with the fuel mileage. I have friends with triple 300 and a larger boat that get much better. I also recently discovered they claim 80 gallon fresh water tank and have never been able to put more than 43.5 gallons of water in at complete empty. Does any one else have the same discrepancies ? I do want to make it clear I love my boat and I know its heavy and takes a lot to get it going.

 

[dbsea]

I understand that I have a diesel inboard (D6-435) on my C30-CB, but these numbers y'all are talking about seem crazy to me. My boat is 11,000lbs dry, and I also have a 3/4 flybridge enclosure which adds significant windage. I'm sure I'm much closer to 13,000lbs+ with a full fuel tank, full water tank, and the boat loaded up with gear. I consistently see 1-1.5mpg with my boat at 16kn, almost never less than 1mpg unless the current is really hard against me. Probably hard to compare when you are talking about 25/45mph speeds. I almost wonder if you have a trim or other issue with those kind of numbers...

With regards to the water tank, my understanding is that on the 30ft boats, they all use a 60 gallon water tank. The additional 20 gallons is calculated by adding on the 11g hot water tank, the accumulator (if you have one), and all the tubing the water flows through. if my tank is empty, I can consistently add 60 gallons, more would depend on if the hot water heater is full or not, and if the system is pressurized.

 

[Ed604]

I am happy to share what I see, I think that there was some games with knots vs. statute miles being played by the marketing department at Fluid Motion. I have the stock props that came with the boat, and it is a 2019 c302.

I have never seen a better sustained MPG of better than 1.2.

I had my Yamaha engine display set to Miles per gallon as opposed to Nautical Miles per gallon and I am seeing the following stats/results.

At my best cruise speed the engines are turning 4300rpm and, at this level, the speed will be around 30 - 33mph SOG and I will see between 1 - 1.2MPG The fuel burn will be roughly around 27 - 30gallons per hour

Going slower with this hull doesn't really help much until you get down to speeds that I just wouldn't want to travel at due to time constraints. I find that the engines are trimmed all the way down and I simply leave them there. trimming up doesn't really help like on other boats?

I was holding some hope for what Sharrow props might be able to help with at RPM level of 3500 - 3800 I was hoping to see better speeds due to the increased grip and the ability maintain "on plane" at lower speeds.

I still love the boat! It really does a lot of what I need with a very cool layout.
But, with that said, she is THIRSTY, that is for certain.

regards,
Ed604

 

[Danation]

"Hey fellow boaters! I'm in the process of purchase a 2018 Cutwater 302 Coupe with twin Yamaha 300s and finding conflicting information about its fuel consumption. The official stats say 1.3 mpg, yet there's talk of as low as 0.8 mpg on this forum, with the dealer is quoting a solid 1 mpg. Anyone here with the same model who can share their cruising mpg? Looking forward to your real-life numbers!"

We own a 2020 Cutwater 32, and I can share some real-life numbers that might help you out. Here's what we've experienced:

I was told that the boat tested by Yamaha was much lighter than the ones being manufactured today, probably an early model without a rear bulkhead, which can be misleading. I have never see 1.3mpg

In our experience, we consistently get between 0.7 and 1.0 mpg, depending on the fuel/water load and sea state. On rare occasions, I've seen 1.1 mpg when coming in on empty. We usually run around 40 mph at 4500 rpm; anything less tends to drop off plane. This is also with the upgrade to the Lenco Auto Glide controls for the trim tabs.

Late last summer, we upgraded to the Sharrows. Although we haven't put a ton of hours on the boat since, we've been seeing a range of 0.9 to 1.1 mpg, roughly a 25% increase in fuel economy. Our running speed is now 35 mph at 4000 rpm, and it stays on plane easily.

Hope this helps!