Cost comparison using Gas Consumption

[RobL]

I'm looking to move from a 2014 R5 (VP 380) to a 2012 323 (twin VP 8.1 400 HP) how do I compare gas consumption? I'm trying to determine cost differences between the two and this seems to be the most difficult to quantify. I recognize there will be an increase in cost, but how could I compare (without having access to either boat in the near future).

[jhnmdahl]

I'd find similarly-equipped boats on review sites like boattest.com and look at their fuel usage charts if you can't find direct reviews of the boats you're interested in. Manufacturers don't usually provide fuel efficiency charts, but better review sites sometimes do.

John

edit: Boattest is subscription-only now, but a prior public review on archive.org says in part regarding a 323 with dual 8.1L:

Test Numbers: We tested this boat on Miami’s Biscayne Bay with four people on board, 80% fuel (data courtesy of EVC) and no water in the tank. Test weight was 13,835 lbs (6,275 kgs). I found her best cruise to be at 3000 rpm running 34.2 miles-per-hour. At cruise speed, she burns about 22 gallons-per-hour getting 1.55 mpg for a range of 243 miles with a 10% reserve.

See https://web.archive.org/web/20150716063 ... px?ID=2462 for more info

[RobL]

Perfect, hadn't thought of that. Thank you.

[MnLakeBum]

I'm looking to move from a 2014 R5 (VP 380) to a 2012 323 (twin VP 8.1 400 HP) how do I compare gas consumption? I'm trying to determine cost differences between the two and this seems to be the most difficult to quantify. I recognize there will be an increase in cost, but how could I compare (without having access to either boat in the near future).

Some companies like Boston Whaler have the performance data on their websites. I’m looking at upgrading my FL boat from a 24’ Whaler to a 32 or 35 footer. As a general rule if you are doubling the HP and doubling the weight of the boat, you will burn twice as much fuel. In your case the weight of the boat is more than double so I would expect at least twice as much for fuel costs.

Here’s the difference between a 24 foot Whaler and a 32 footer with twin 300’s vs. a single 300 on the smaller one. I would expect a 2012 323 to burn more fuel than this 32 foot Whaler as it has more HP and weighs 2,000 lbs more.

[jwill323]

I moved from a Sea Ray 280 BR single Merc 454 mag Bravo 3 to a Cobalt 323 twin 8.1 496 Mag HO with bravo 3X drives. I don't think I'm double the fuel but I would say it's probably more in line with about 1.5 times. With the twins you aren't working the engines as hard and I'm more able to stay in an efficient crusing RPM range due to the size of the boat. On the other hand I have been on the water more and going farther, also running the gen set. At the end of the day am i spending more on fuel? Yes, but I'm having more fun!

Feel free to reach out with any questions on the 323, I have been through mine really thoroughly in the last year and i'm happy to help with anything. Its a great boat!

[MnLakeBum]

I did a quick search and found these performance charts for an R5 and an R33 with twin Volvo 380’s. I didn’t find any performance data on the 323 with twin 8.1 400’s but they will likely burn a bit more fuel than the twin 380’s.

At 34 mph the R5 is at 2.82 and the R33 is at 1.55mpg

[jwill323]

The thing to consider is depending the water conditions can you stay at that most efficient cruise RPM in either boat. What i found was that at Lake of the Ozarks in our smaller boat i was more on and off the throttle because of water conditions leading to a much less efficient cruise. With a boat that is almost 6 feet longer and twice the weight i could basically set it at 3300-3500 rpm and cruise comfortably. By avoiding the on and off throttle work there is some efficiency gains. Again not saying it's more efficient than the single engine but there is more to the story than just straight fuel burn numbers. Again not sure what the water conditions are where you boat at but if you encounter heavy weekend traffic like i do you're able to deal with it better in a bigger boat and maintain your optimum cruise speed.

[RobL]

I did a quick search and found these performance charts for an R5 and an R33 with twin Volvo 380’s. I didn’t find any performance data on the 323 with twin 8.1 400’s but they will likely burn a bit more fuel than the twin 380’s.

At 34 mph the R5 is at 2.82 and the R33 is at 1.55mpg

The boattest.com site shows a 2013 Cobalt with 8.1 getting 1.55 mpg as well with 2x375hp VP 8.1 (exactly same as the R33 above). The boat I'm interested in is a 2012 with 2x400hp VP 8.1 so I'm guessing slight decrease? So by my novice logic, a SWAG ballpark figure is twice the amount of gas in the 323 as my R5?

Cobalt 323 (2013-) Test Result Highlights

• Top speed for the Cobalt 323 (2013-) is 54.1 mph (87.1 kph), burning 62.0 gallons per hour (gph) or 234.67 liters per hour (lph).
• Best cruise for the Cobalt 323 (2013-) is 34.2 mph (55 kph), and the boat gets 1.55 miles per gallon (mpg) or 0.66 kilometers per liter (kpl), giving the boat a cruising range of 243 miles (391.07 kilometers).
• Tested power is 2 x 375-hp Volvo Penta 8.1Gi w/sterndrive joystick.

[RobL]

edit: Boattest is subscription-only now, but a prior public review on archive.org says in part regarding a 323 with dual 8.1L:

Test Numbers: We tested this boat on Miami’s Biscayne Bay with four people on board, 80% fuel (data courtesy of EVC) and no water in the tank. Test weight was 13,835 lbs (6,275 kgs). I found her best cruise to be at 3000 rpm running 34.2 miles-per-hour. At cruise speed, she burns about 22 gallons-per-hour getting 1.55 mpg for a range of 243 miles with a 10% reserve.

See https://web.archive.org/web/20150716063 ... px?ID=2462 for more info

Excellent read. I couldn't access video or the spec sheet, but looks like that 1.55mpg is the number I was seeking. Thank you.

[RobL]

The thing to consider is depending the water conditions can you stay at that most efficient cruise RPM in either boat. What i found was that at Lake of the Ozarks in our smaller boat i was more on and off the throttle because of water conditions leading to a much less efficient cruise. With a boat that is almost 6 feet longer and twice the weight i could basically set it at 3300-3500 rpm and cruise comfortably. By avoiding the on and off throttle work there is some efficiency gains. Again not saying it's more efficient than the single engine but there is more to the story than just straight fuel burn numbers. Again not sure what the water conditions are where you boat at but if you encounter heavy weekend traffic like i do you're able to deal with it better in a bigger boat and maintain your optimum cruise speed.

We're on the Potomac River outside DC and it can get choppy. In fact, we moved up from a 19' Chapparal that I dearly loved to the 25' Cobalt specifically for the water which it handles like a champ. I'd like to take her down into the Chesapeake Bay but that's pushing it in my opinion. We did have the R5 off the coast of Maine island-hopping and that was a dream!

[RobL]

I did a quick search and found these performance charts for an R5 and an R33 with twin Volvo 380’s. I didn’t find any performance data on the 323 with twin 8.1 400’s but they will likely burn a bit more fuel than the twin 380’s.

At 34 mph the R5 is at 2.82 and the R33 is at 1.55mpg

Do you think there is much difference in build quality between your 2018 R5 and my 2014? Company changed hands and there was some concern about drop in quality. (I was thinking if I bought the 323 and decided it wasn't for me, I'd drop back down in a later model R5)

[MnLakeBum]

I did a quick search and found these performance charts for an R5 and an R33 with twin Volvo 380’s. I didn’t find any performance data on the 323 with twin 8.1 400’s but they will likely burn a bit more fuel than the twin 380’s.

At 34 mph the R5 is at 2.82 and the R33 is at 1.55mpg

Do you think there is much difference in build quality between your 2018 R5 and my 2014? Company changed hands and there was some concern about drop in quality. (I was thinking if I bought the 323 and decided it wasn't for me, I'd drop back down in a later model R5)

Cobalt got sold the summer of 2017 and my boat was built in early 2018 and I’m not seeing any quality drop with my boat. I’ve been in two or three R6 models from 2021 and to me the quality seemed the same although there have been a lot of Cobalt owners who feel differently about the construction/quality control of the newer boats from Cobalt. I will say the manual tower design on my buddies R6 is a huge hassle compared to the electric tower on my R5 but I believe he could have opted for a powered one as well.

Off topic: I haven’t had much time on 30-40 foot Cobalts but I’ve been on quite a few larger ocean boats that size the last 2 years including ones from TIara, Grady White, Formula, and Boston Whaler. If I’m shopping in that 32-38 foot range for use on one of the Great Lakes or another large body of water I’d be looking at those brands and others maybe over a Cobalt. I love our R5 and feel like it’s the best premium lake boat option for our 14,000 acre lake but when I buy something in that 35 foot range in the next year or two for Florida, it will likely be a slightly used dual console Boston Whaler or Grady White.

[RobL]

Off topic: I haven’t had much time on 30-40 foot Cobalts but I’ve been on quite a few larger ocean boats that size the last 2 years including ones from TIara, Grady White, Formula, and Boston Whaler. If I’m shopping in that 32-38 foot range for use on one of the Great Lakes or another large body of water I’d be looking at those brands and others maybe over a Cobalt. I love our R5 and feel like it’s the best premium lake boat option for our 14,000 acre lake but when I buy something in that 35 foot range in the next year or two for Florida, it will likely be a slightly used dual console Boston Whaler or Grady White.

Interesting suggestion, I’ll have to open my search parameters. We’re looking to buy a retirement home in 2025 and unclear if it will be on 20k acre Smith Mountain Lake (R5 is perfect there) or we’re going somewhere on the ICW or Chesapeake Bay. The appeal of the 323 is the similar layout of the R5 from the helm back. We might have to own 2 boats this summer (oh boy)

Only downside of R5 is lack of enclosure, not necessarily for overnight, but to escape a sudden rain shower or blazing heat.

[MnLakeBum]

Off topic: I haven’t had much time on 30-40 foot Cobalts but I’ve been on quite a few larger ocean boats that size the last 2 years including ones from TIara, Grady White, Formula, and Boston Whaler. If I’m shopping in that 32-38 foot range for use on one of the Great Lakes or another large body of water I’d be looking at those brands and others maybe over a Cobalt. I love our R5 and feel like it’s the best premium lake boat option for our 14,000 acre lake but when I buy something in that 35 foot range in the next year or two for Florida, it will likely be a slightly used dual console Boston Whaler or Grady White.

Interesting suggestion, I’ll have to open my search parameters. We’re looking to buy a retirement home in 2025 and unclear if it will be on 20k acre Smith Mountain Lake (R5 is perfect there) or we’re going somewhere on the ICW or Chesapeake Bay. The appeal of the 323 is the similar layout of the R5 from the helm back. We might have to own 2 boats this summer (oh boy)

Only downside of R5 is lack of enclosure, not necessarily for overnight, but to escape a sudden rain shower or blazing heat.

Yep, that R5 is perfect for your 20k acre lake. I’m new to the saltwater boating as I just got our Boston Whaler in Florida 15 months ago. I hauled it back to Minnesota last April so I had the entire summer to compare it to our R5 that it was parked next to until I shipped it back to Florida in October. It handles the choppy days on our 14k acre lake better than the R5 and they are nearly identical in size/weight with the Whaler being a foot shorter but 300 pounds heavier than the R5. I was on a 320 Vantage recently in 3+ footers on the Gulf here in Naples and it handled the waves really well on a day where my 24 footer would have been pretty miserable to be in. A very similar Grady White I was on last fall was maybe even a bit better riding in the waves than the Whaler.

There are lots of great options out there so it’s worth looking at more than one brand. If your boating needs include sleeping quarters up front in that 32-35 foot range I still think a Cobalt is one of the best options. For the ocean or very large freshwater lakes, I like some of the other brands better.

A couple pics of our Whaler that is 24’5” and a link to the 32 foot version of it. The 320 Vantage a few years old with low hours are about $300k so they are damn expensive and hold their value well. FWIW, my goal is to buy a Boston Whaler 350 Realm(35’6” loa) as soon as I’m off the waiting list for a larger slip at our condo.

[RobL]

Good looking boat, looks like lots of run in the bow.

There are lots of great options out there so it’s worth looking at more than one brand. If your boating needs include sleeping quarters up front in that 32-35 foot range I still think a Cobalt is one of the best options. For the ocean or very large freshwater lakes, I like some of the other brands better.

Darnit, I dipped my toe in the deep end and looked at other brands and ran across Formula 350 Crossover Bowrider which honestly knocks it out of the park for us. Just need to double+ our available budget

btw testing a Cobalt 323 this weekend, stoked.