View Full Version : Surf System Boat Fuel Consumption

02-16-2015, 10:02 AM
If you normally ballast a boat with 2,500 to 3,000 lbs to make a good surf-wake, a comparable surf system wake with evenly weighted ballast would be around 4,000 to 4,500 lbs. And, when you consider the drag of the surf tab, fuel consumption would be greater in surf system boat.

I've read fuel consumption estimates on surf system boats could average 8-12 GPH (gallons per hour) while surfing. This seems high to me, however I don't own a surf system boat --- yet.

Moomba promotes the improved fuel consumption/economy of the Raptor motor. Does anyone have experience with fuel consumption on a new Mojo surf system boat with the Raptor?

Please, no cheesy comments that anyone concerned about fuel consumption/economy can't afford a boat. That's not the case.

02-16-2015, 10:08 AM
After spending a lot of time in the new Mojo late last summer, I think I can reasonably say that the new Raptor motor has such great low end torque that even with added weight and drag for surfing, it doesn't work very hard. Therefore, compared to a boat with 5.7L or smaller engine that needs to work harder the Mojo with the Raptor will have better fuel economy. We never had any fuel issues (it running out quicker than we expected) when we surfed the Mojo. The engine definitely makes a difference

02-16-2015, 10:38 AM
I appreciate the positive feedback on the Raptor. Wake9.com has a fuel consumption calculator so you can quickly compare consumption vs cost.

I don't want to overstate the issue. If you average 60 hours of use per year, the cost difference between 10 GPH vs 5 GPH at 3.50 per gallon is about $175 per month or $1,050 per season - really not a big deal.

My primary issue is the hassle of filling up the boat. Also not a big deal but like most folks time is always in short supply.

Thanks again.

02-16-2015, 11:46 AM
We've ran a lot of boats with the old 5.7L that also had surf systems (Supra SA) and you really can tell a difference with the Raptor just because it's not running the same amount of RPMs as the smaller engines.

I really believe the Raptor will make a sizeable difference in fuel economy, from my own experience

02-16-2015, 12:19 PM
My Experience with GPH is its just like MPG in trucks, its all about your driving style, prop, and weights. No two boats will be the same, this is a HUGE reason why Idmar and other companies won't post anything concrete about fuel, consumption. If you notice until recently you didn't get torque values either.

With our 08 LSV 5.7 running the regular Wake Prop, 14x14.5 and running average of 3K ballast and 5 adults 7gpm was the average. This was figured due to I fill after every outing.

When I switched to a 2079 prop, basically more acceleration, less top end my fuel consumption dropped to 6gph.

Now I have the Mojo and its first season was Same Wake Prop as listed above.
Weight for surfing 3500 ballast 400 lead and 8 adults normally.
GPH average at 4-5 now.

In Year 14 We upgraded the prop same way to more low end power less top end, and fuel consumption stayed the same basically.

What a lot of people don't consider when thinking about fuel consumption is its not really surfing that sucks up all your fuel. Yes you run a lot more ballast but you are running at a slow speed. These are 1 gear engines, lower speed means lower RPM and yes you might have more throttle but honestly its not a lot.

Wake Boarding uses a TON more fuel then surfing. Most run ballast during this as well, and if you look into the engines you can find fuel usage numbers per RPM such as below, on the Tige even. This is Wake 9s boat. I have even spent several hours surfing with them on multiple occasions as we are personal friends of the Garcia's.

With the 415-hp Indmar M60 engine powering our test boat we reached a top speed at 5400 rpm of 44.7 mph. At that speed she was burning 30.75 gph giving us a range of 63 miles. So that will get us out to the play area, but just how long can we play for?

Surf Speed and Surf Shape

Remember, this is a pro surf boat, so we’ll top off the ballast sacs and run between, say, 9…9.5 to 11.5 mph. 9 mph will give a shorter wake, but a taller one that beginners like as it gives more push. That speed will show a fuel burn of around 3 gph and the Z3 can keep doing it for well over 14 hours. Bump it up to the high 10s or low 11s and the wave lengthens out giving more room for free styling and moving around. That produces a fuel burn of around 4 gph which she can keep up for nearly 11 hours.


You can expect to be burning 10-20GPH wake boarding.

If you want to compare tubing we have done several tests when we pull our charity events and pretty much all day is pulling a tube from 10-18 mph. This burns apx 40 gallons of fuel in a 3 hour period. Thats 13 GPH and no ballast with 4 adults and 4 kids average.

I also have noticed a lot pf people seem to travel a bit of distance to get to their favorite boarding spot and this is done at wake speed 20-25mph and this is eating a lot of fuel.

We tend to do the slow cruise all the time. At LBC which is a large lake we slow cruise it to our spot and tend to only cruise at higher speeds when we are beating weather or a seriously upset stomach lol.

Honestly trying to figure out GPH in a boat is about as reliable as the threads we get about Whats your Trucks MPG stuff. To many factors.

02-16-2015, 02:04 PM
I pretty much figure if we are out for 3-4hrs on a weekend day, it's 20 gallons. between cruising around and surfing, seems to be the norm.

glad gas is down to $2.25. hope it stays there all summer.

02-16-2015, 02:05 PM
I pretty much figure if we are out for 3-4hrs on a weekend day, it's 20 gallons. between cruising around and surfing, seems to be the norm.

glad gas is down to $2.25. hope it stays there all summer.

Amen to that. Sub 2.50 gas