Best Cruising Speed

[Joe32586]

I live in a place where it can be a few miles between your house, the beach bar, and the best water to ski/ride on. Thus I find myself just cruising sometimes and I often wonder what the best cruising speed is. I'd like to use as little fuel as possible when just transiting.

I'm sure the boat/ engine/prop/weight all have something to do with it.

I have a sporster with a 310 carb, a 3 blade prop (Not sure exact pitch: most likely 13x13), and my WOT Top speed is about 48 @ 4900 rpm.

I think around 25-28mph seems best, fast enough I'm not plowing water like wakeboard speed but not fast enough to open the secondary barrels in the carb.

Any insight/opinions would be greatly appreciated.

Also: any suggestions for a prop which may help cruising?

[aaudii5150]

I've found that the HH in our 23 LSV likes to run about 3200 rpms. Sometimes we run 10-15 miles at a time in some high traffic areas. This puts me about 26-28 mph and seems to cut right through the chop...... I haven't done the math on Gallons/Hour but seems to do alright about 5 G/H with several people in the boat.....

[JohnDoe]

I recall an mpg study on dds in trailer boats or something like that which showed that 2800 rpm was ideal. There are other factors however including boat weight and prop pitch which can affect ideal.

[Jimmypooh]

My guess on gas consumption would be lowest RPM while still on plane.

[jetskipro550]

WOT

[Coach Mike]

I tend to be in the 25 to 30 mph range to get where I'm going too. Fast enough to not have to be screaming over engine noise and can still hear music. I agree on efficiency comments as well.

[JohnDoe]

WOT

WOT for best fuel economy? That's the worst in these boats.

[aaudii5150]

I tend to be in the 25 to 30 mph range to get where I'm going too. Fast enough to not have to be screaming over engine noise and can still hear music. I agree on efficiency comments as well.

I can't even hear the engine over the stereo until I hit WOT.......

[Malibudude]

WOT

Wedge 3/4 down as well.

[BlastRlxi]

My guess would be about 30 mph.

[VinRLX]

WOT

Wedge 3/4 down as well.

And LOTS of VAB.

Best efficiency does vary by hull, motor, prop, etc. However, from the various studies I've read, v-drives tend to be best from 3,000-3,500 RPM and DDs from 2,500-3,000. Within that range, there is of course a sweet spot, but the difference may be .1 MPG.

[ed obermeier]

I recall an mpg study on dds in trailer boats or something like that which showed that 2800 rpm was ideal. There are other factors however including boat weight and prop pitch which can affect ideal.

Way back in the day when I still owned an I/O (Long time ago in a land far far away...) I too had a subscriptinn to Trailer Boats Mag. They did a lot of testing on stuff like that and as I recall JohnDoe is correct, 2800 - 3000 rpm's for a V-8 engine was the most efficient cruising range. Maybe something on their web site someone could dig out if interested?

Ed

[brettpendl]

This topic came up here a couple years ago, or maybe on Wakeworld. I can't remember. What was really interesting, was someone posted alot of graphs for different engines with fuel comsumption compared to speed. I have the HH on my LSV, and remembered seeing that gas comsumption increased comparably with speed almost all the way to around 36 to 40 MPH. Past that gas consumption increased exponentially. It was rediculous, and now the only time I run over 40 mph is to empty the gas tank.

[electricjohn]

Use 'optimum cruising speed' with the search function. It will bring you to a chart I posted.

Edited June 3, 2009 by electricjohn

[D-GOOSE]

WOT

WOT for best fuel economy? That's the worst in these boats.

No WOT is the best

I like to run about 3000-3200RPM no matter what prop I'm running.

[surferbobo]

i read years ago a study on the Malibu monsoon engine that 28mph was the best cruising speed.

[DUKENO1]

I get the best fuel economy if my engine is turned off and I am floating in a cove holding a beer in my hand!! Seriously, the only time I really notice significant fuel usage is wakeboarding with that dang wedge down! You can almost watch the needle moving towards E!

[DooKoo]

For best gas mileage:

1. Jettison all gear and passengers (but remember not to forget about them).

2. The hottest girl to stay at the bow to help with 'aerodynamic airflow' around the boat.

3. Crank up the music as the sound waves pushing backward help with efficiency (kind of like Star Trek impulse drives).

Remember to do this several times until you find the right position(s) for the 'aerodynamic' bow aid and music level/type.

Good luck!

ps. your gas mileage may vary but you are guaranteed a good time.

[bigD]

My guess on gas consumption would be lowest RPM while still on plane.

Or WOT with stereo volume at 11