Prop for best gas efficiently

[u0053157]

I have a 2016 G23 with PCM 550 HP engine and exclusively use it at Lake Powell, AZ/UT. The elevation is approximately 3500 ft above sea level. I currently have the standard acme 2561 prop, but it burns through gas. Is there a better prop/pitch that will offer better gas efficiency at this elevation?

[Nautiquehunter]

Boats run at full load all the time. If you are surfing its even worse . You have one of the biggest, heaviest boats Nautique makes combine that with a 550 engine and fuel economy is out the door. My 08 210 uses 40 gallons of fuel pulling hard most of the day its half the weight and half the engine you have?

[Jonny Quest]

My neighbor runs a 2019 SAN G25. At Powell, we made a run from Padre Bay to Wahweep. My neighbor ran at wide-open-throttle (WOT) the whole way. I was shocked to see the engine RPMs running 5,500. The boat drive train is propped low for boarding / surfing so speed is an afterthought. At WOT he ran through a stupid amount of fuel. Again I was shocked.

I don’t think that a new prop will solve your fuel consumption, but rather ballast weight and RPM. Cruising (lightly loaded) at 3,000 ish RPM will likely produce the best fuel economy.

it also begs the question: with the insane cost of those Nautique surf barges, one would assume that fuel cost is not a big consideration…

JQ

[Tchur1]

My neighbor runs a 2019 SAN G25. At Powell, we made a run from Padre Bay to Wahweep. My neighbor ran at wide-open-throttle (WOT) the whole way. I was shocked to see the engine RPMs running 5,500. The boat drive train is propped low for boarding / surfing so speed is an afterthought. At WOT he ran through a stupid amount of fuel. Again I was shocked.

I don’t think that a new prop will solve your fuel consumption, but rather ballast weight and RPM. Cruising (lightly loaded) at 3,000 ish RPM will likely produce the best fuel economy.

it also begs the question: with the insane cost of those Nautique surf barges, one would assume that fuel cost is not a big consideration…

JQ

This argument frustrates me, even if you can afford a new surf boat doesn't mean you want to needlessly spend on gas. We are fortunate enough to own a newer surf boat but fuel consumption is still a consideration, and if you can optimize for it, why not?

[bturner]

I recall the story about the guy that was looking at a Ferrari and asked the salesmen "what kind of gas mileage does it get?" The response was that if you had to ask about gas you can't afford the car.

Be as frustrated as you want but the simple truth is that he bought a G23 which is designed to plow water and make a big wake. Add to that altitude and the very good possibility that he's added ballast to get that "perfect surf wake you just can't get without additional ballast" and pretty much there is no optimizing for gas mileage. It's going to suck no matter what you do and that comes with the territory. Sure you can play with the prop a bit and pitch it down a bit but that really isn't an efficiency thing, it's more a performance tweak as you're going to have to hammer it to go faster than 20MPH. The truth here being is that the prop pitch giveth and taketh away. Unless you plan to do only one kind of boating or you plain don't have the performance at altitude you're better off staying with something made for general surfing.

Another alternative that would have near the same result as a new prop would be to remove weight from the boat. Get rid of everything you're not using and only run the minimum ballast you need for the desired activity. Leave the 200 gallon coolers full of beverages and ice, the extra food, clothes, ski equipment, tackle and anything else you won't be using at home. We do this with our slalom boat but doubt if anyone with a surf ship is going to give up any of those things though.

If you're going to be at altitude most of the time I hear that running boosted engines is the magic. Whatever you lose in atmosphere from altitude is made up for by boost.

At the end of the day if you end up burning say 10 gallons less and save $30 doing all you can to optimize that $150K - $250K surf ship does it really matter? Chances are that if you own a G23 or Paragon that $30 probably took you about 15 minutes to make. Got to keep everything in perspective.

On the other hand if you're doing it to try and be "Green", well I don't know how to even start with that......

[SilentSeven]

I have a 2016 G23 with PCM 550 HP engine and exclusively use it at Lake Powell, AZ/UT. The elevation is approximately 3500 ft above sea level. I currently have the standard acme 2561 prop, but it burns through gas. Is there a better prop/pitch that will offer better gas efficiency at this elevation?

To help the OP, I think you should talk to either your Nautique dealer or a maybe a prop specialist like Acme or Wakermakers etc. They might have a suggestion on a better prop given the altitude.

But I think bturner is correct in saying that it's already an uphill fight and you're rubbing the kitty backwards. Trying to get fuel economy out of a surf ship is gonna be difficult - you might get a marginal improvement at best. My suggestion...dump the jumbotron and start skiing.

[Tchur1]

I recall the story about the guy that was looking at a Ferrari and asked the salesmen "what kind of gas mileage does it get?" The response was that if you had to ask about gas you can't afford the car.

Be as frustrated as you want but the simple truth is that he bought a G23 which is designed to plow water and make a big wake. Add to that altitude and the very good possibility that he's added ballast to get that "perfect surf wake you just can't get without additional ballast" and pretty much there is no optimizing for gas mileage. It's going to suck no matter what you do and that comes with the territory. Sure you can play with the prop a bit and pitch it down a bit but that really isn't an efficiency thing, it's more a performance tweak as you're going to have to hammer it to go faster than 20MPH. The truth here being is that the prop pitch giveth and taketh away. Unless you plan to do only one kind of boating or you plain don't have the performance at altitude you're better off staying with something made for general surfing.

Another alternative that would have near the same result as a new prop would be to remove weight from the boat. Get rid of everything you're not using and only run the minimum ballast you need for the desired activity. Leave the 200 gallon coolers full of beverages and ice, the extra food, clothes, ski equipment, tackle and anything else you won't be using at home. We do this with our slalom boat but doubt if anyone with a surf ship is going to give up any of those things though.

If you're going to be at altitude most of the time I hear that running boosted engines is the magic. Whatever you lose in atmosphere from altitude is made up for by boost.

At the end of the day if you end up burning say 10 gallons less and save $30 doing all you can to optimize that $150K - $250K surf ship does it really matter? Chances are that if you own a G23 or Paragon that $30 probably took you about 15 minutes to make. Got to keep everything in perspective.

On the other hand if you're doing it to try and be "Green", well I don't know how to even start with that......

I never said changing props is going to take the fuel consumption of a G and turn it into a prius, never going to happen. If we(or OP) put 100-150 hours on our boat this summer and can reduce fuel burn by 10% that adds up to a lot more than $30. Is it going to turn into life changing money, no, but why throw money away if you can make the change and reduce operating for the time you own the boat?

[hal2814]

It depends. As a general rule for fuel efficiency you want the pitch as high as you can get it without lugging the engine. All things being equal a high pitch prop will turn lower RPMs for the same speed therefore decreasing fuel burn. The 2561 is a 17x17. A 17x19 will burn less fuel in most circumstances. So for example 4000 rpm at 17p should be roughly 22-23mph. Moving to a 19p that same speed would put you around 3600rpm. You are in theory saving 10% on fuel at that speed. But real world numbers don’t always work that way, especially for surf boats. We load these things up with ballast. The same principle still applies but if we overprop (pitch too high) we lug the engine and end up burning more fuel, not less. So if you want to try to save a little fuel and are ok that it might take more time to get up to surf speed when loaded you could try a 19p prop and see how that works. Not sure how far people have pushed the pitch though and I’m not 100% sure ACME makes a 17x21

[Tchur1]

In my experience with my boat, stock prop was OJ 18x16 and full ballast + 600 lbs of lead and 2-4 people in the boat we run about 3600 RPMs. Moving to OJ 18x17 allows us to still plane quick enough but drops surf RPMs down to about 3200 (about 12% difference). This is just my experience and others milage may vary. We predominantly surf and not much cruising so top speed is of little interest to me.

For the OP reach out to ACME and see what they recommend for your use case and you can determine if its worth it or not.

[bturner]

The problem is that in all honestly you probably won't save near 10%. You'll have the investment in the prop and as stated before playing with pitch will buy you performance but rarely MPG and if so it's doubtful it will be 5% let alone 10%. Wrong boat, wrong hull and wrong water sports activity. Honestly you'd be better off looking for cheaper places to buy gas or methods of fueling up if you're stuck buying at a marina now.

If you we're telling me you're going on vacation on a large body of water and plan on doing mostly cruising it would probably make sense to change props. I did this with my previous boat when changing from the little inland like I'm on most of the year to Lake Erie. On the inland lake I surf/wake board 95% and when we go out for a cruise it's mostly short distances at idle. My low pitch prop works great here. On Lake Erie it's near the opposite with cruising about 80% and surfing/wake boarding maybe 10% with slalom the other 10%.

With that kind of mix I'll run a higher pitch prop as I know I'll be running about 28mph for extended periods and will suffer with the performance for surfing and such. With this kind of mix you will see a difference when cruising but I'm cruising at the same speed regardless of props.

So if it works with cruising why won't it work with that high altitude stump puller you say? Well in theory it should but a lot has to do with habit and the other is the mix rarely ends up being the same. That stump puller will deliver performance and should save you on gas IF you were trying to achieve the same performance as before but be honest, you probably won't. You'll still end up putting the hammer down, burning just as much gas only now it will perform better. Then if your cruising, on say Lake Tahoe, you'll be turning more RPM to go the same cruising speed you're used to and burn more gas there as well. How do I know all this is true 9 times out of 10 you say? Been there with multiple boats, set the same things up for others with multiple boats with the same results. Been doing this for over 25 years with inboards, outboards and I/Os.

Don't believe me? Call Acme or OJ and ask them about their MPG guarantee with their prop recommendation and wait for the silence or laughter in the background. What you'll get is that it should get better MPH. But even if it did how would you know? With a car it's fairly easy, distance over consumption. Fill up, get on the freeway, drive, fill up again, do the math and you'll know your highway mileage. It's not so easy with a boat. Sure you can install a flow meter but you don't have that constant of the freeway. You have greater variables like water conditions, activities, wind, number of guests, gear and the list goes on. The best you'll be able to do is tell yourself that it "feels" like I'm getting better economy (I've done this as well, especially when the wife asks about the credit card charge for the new prop. Then I say it's paying for itself).

All this to get back to the statement that changing props should be primarily done for performance. If you're looking for some magic 10% MPG gain with a surf ship I highly doubt you'll find it with a prop (but I have heard magnets on the fuel lines are amazing) or actually know if you've achieved it.

But hey, I could be completely wrong.

[Tchur1]

I think this has gotten off the rails a bit, I don't disagree with what you are saying that across a broad range of activities its really hard to determine if propping your boat will be more fuel efficient.

In my experience with how we use our boat we have seen about a 10% savings but thats in our specific use case. As I stated, milage may very depending on how they use.

My original statement was that its a poor argument to say "if youre trying to save gas, you cant afford the boat" I can afford a nice surf boat, but im still conscious of fuel burn and I dont think thats insane.

OP was asking if if there is a better prop for his use case, and based on your experience the answer is no.

[ESP]

This is off the rails a bit. You really don’t say what your primary use of the boat is, how much ballast. But the PCM 550’s don’t sip fuel the difference in prop will give you change in performance based on your intended use. We just purchased a GS 22 and I will say the PCM motor is a nice runner, it is not as efficient as the Raptor 6.2 that we had previously. The 2561 is a recreational everything prop, you could try a 3077 which is a Wakeboard/Wakesurf prop you will find better performance and it may help with fuel use if you are lugging. Could also try the 2749 way better bottom end and mid but no top end. Either way the boat is 8400lbs from the factory with ballast and if you are loading it to may capacity with people (15) its just tough on fuel economy. When surfing we average 6 gallons per hour in our GS at 3400 RPM using the Acme 1235 with our ballast setup 8400lbs. Give wakemakers a call we have always had good luck with their recommendations.

[srock]

I recall the story about the guy that was looking at a Ferrari and asked the salesmen "what kind of gas mileage does it get?" The response was that if you had to ask about gas you can't afford the car.

Be as frustrated as you want but the simple truth is that he bought a G23 which is designed to plow water and make a big wake. Add to that altitude and the very good possibility that he's added ballast to get that "perfect surf wake you just can't get without additional ballast" and pretty much there is no optimizing for gas mileage. It's going to suck no matter what you do and that comes with the territory. Sure you can play with the prop a bit and pitch it down a bit but that really isn't an efficiency thing, it's more a performance tweak as you're going to have to hammer it to go faster than 20MPH. The truth here being is that the prop pitch giveth and taketh away. Unless you plan to do only one kind of boating or you plain don't have the performance at altitude you're better off staying with something made for general surfing.

Another alternative that would have near the same result as a new prop would be to remove weight from the boat. Get rid of everything you're not using and only run the minimum ballast you need for the desired activity. Leave the 200 gallon coolers full of beverages and ice, the extra food, clothes, ski equipment, tackle and anything else you won't be using at home. We do this with our slalom boat but doubt if anyone with a surf ship is going to give up any of those things though.

If you're going to be at altitude most of the time I hear that running boosted engines is the magic. Whatever you lose in atmosphere from altitude is made up for by boost.

At the end of the day if you end up burning say 10 gallons less and save $30 doing all you can to optimize that $150K - $250K surf ship does it really matter? Chances are that if you own a G23 or Paragon that $30 probably took you about 15 minutes to make. Got to keep everything in perspective.

On the other hand if you're doing it to try and be "Green", well I don't know how to even start with that......

Its not always about money.

I rented a house boat in Powel and towed the Nautank. I definitely wanted to understand and control my burn rate and more important when to go fill up.

I have gone places where it was not an issue of having a fat wallet but making it to the "next" fuel stop. Or, I am pulling the boat from the lift and I prefer to fill it on the trailer. Or who wants to sit at the pump with all these people in line if we can make it to the springs and back. I have also timed my purchase to avoid trailering long distances with the extra weight.

I figured out my optimal burn rate and how much fuel is actually in the boat based on an always inaccurate fuel gauge.