Performance question

F

Fishcatcher907

New member
Alright folks I’ve got a question.

So this year I got a 22’ cruiser with a 2004 90hp Honda.
We just finished a 154 mile round trip in PWS.
It was 4 adult males + gear (Coolers and tents). I used around 57 gallons of fuel.
The question is this...
would that be considered good, bad or average fuel consumption?
I was cruising @4200rpm and doing a little over 11 knots

Is there a better pitch prop for heavy loads?

The next question is.

Do twins handle bigger loads better?

Thanks to all that pitch in and have a happy and safe Fourth of July!

God Bless America
 
Seems a little slow for 11 kts at 4.2k rpm unless you were really heavy. I have a 90 hp Merc and usually try to maintain 4.2k - 4.3k rpm, we recently went out with 4 adults and 2 toddlers in the boat and were cruising at about 15-16 knots at that rpm. Do you have trim tabs or permatrim? I have a hard time getting up to speed without trimming all the way down and trim tabs out if I am stern heavy. We are running a 17” pitch prop
 
So it all depends on what your goals were making the trip to begin with.

It seems a success; you made it w/o injuries, breakdowns or serious
calamity. Some cannot claim that. So, rejoice - enjoy the fireworks.

Sure, better fuel mileage could have been experienced with different
engine/prop/load/boat factors but to what end? And why would four
beer guzzling blokes on a fun trip give a hoot about mpg to begin with?

Aye.
PS: Twin engines usually do not improve fuel economy all things being
equal.
 
It sounds like you were pretty heavy so you didn't do all that bad.

Milage when you are running on Salt water is very decieving so I rarely, no, actually never, look at miles per gallon. (I have tied to more than one dock where it took 3000 RPM just to maintain a static position = equal 0 --no-- miles per gallon.)

If you are concerned about mpg, you can increase that number by running downhill -- with the tidal current. Or, like some do, run slow, hull speed, when you are running with the current, and run at planning speed when you are going upstream.

Harvey
SleepyC :moon
 
I'm cruising the Inside Passage right now on my CD-22 with a Merc 115 4 Stroke EFI. And I'm currently loaded heavy! At hull speeds (4-5 kts) I'm getting 5-6 mpg. (statute miles per gal). On plane I'm getting between 2.5-3 mpg. 11 kts is about 12-13mph. That's not an unreasonable speed. I typically cruise on plane at 13kts or 18 kts. Just the sweet spots on my boat. Back home on local lakes and loaded normally, I average about 3.1-3.4 mpg on plane. So I'd say you are getting pretty standard mileage at your weights and speeds. Colby
 
11 mph is just barely on a plane--and probably not the best speed--you would have been better off to have cranked up the RPM and run at 4800-That should get you up on a plane and in the 13 to 15 mph. Outboards can be run at higher RPM--but...you want to establish what the wide open RPM is with that prop and that load. If it is lugging the engine, then change the prop, to get the WOT RM up to the 5500+ range. You may need 2 props--one for "normal" and one for big loads...

2.7 miles per gallon is not good for a c Dory 22...

Not sure how to assess the 4 men and tents coolers--without more specific weights. We run our boats heavy, with gear and food for a month at times. But only 2 adults...

A 4 blade prop might be better.

Let us know what the WOT RPM is next time you have that load1.
 
Bob, he said 11 kts, not mph. That's 13.2 mph. The 22 does plane ok at that speed. (You might have to go a little faster to get it on plane, but then you can back down and keep it on plane.) The fuel he used is also on par with what I've seen with Midnight Flyer at those speeds and heavy.

BTW, Fishcatcher, you mentioned your speed in kts. Was your mileage in NM or SM? (Nautical or statute?) If in Nautical miles, then you were getting closer to 3smpg, and that seems in comparison to what I get. BTW, I am propped at specs. (Ie, my WOT is where it should be.) I'm currently running a 3 blade, but I have run a 4 blade in the past. The 4 blade gets out of the hole faster, but I'm not sure I really saw any mileage difference. Nothing wrong with running your boat at 4200 RPM or 11 kts if that's what you like to do. I have played a bit with my speeds to try and get the best cruise speed, and that's where I've come up with 13 or 18 kts for my boat. I've found the biggest factor is in where I trim the engine and how I use the trim tabs. I set my power, and then when everything is stable, I adjust the trims to get the best speed. I'm usually in the 4800-5200 range but have also ran around 4000 rpm, still on plane. Colby
 
Thanks for all the input guys. I was running the solas 13” and I’m leaving on another trip on Sunday. I’m going with the 13.5x15x3 on this trip. We’ll see what the difference is.
Thanks again.
 
Did the exact math. If your distance was in Nautical miles, then you were getting about 3.2 mpg (statue miles). That would be very comparable to what I get, and I'd say you were doing well with a loaded boat at that speed! Slow down to 4.5-5 kts (our hull speed on a 22), and I think you'll see your mileage go up to 5-6 smpg! :) Colby
 
hardee":1v476ma0 said:
It sounds like you were pretty heavy so you didn't do all that bad.

Milage when you are running on Salt water is very decieving so I rarely, no, actually never, look at miles per gallon. (I have tied to more than one dock where it took 3000 RPM just to maintain a static position = equal 0 --no-- miles per gallon.)

If you are concerned about mpg, you can increase that number by running downhill -- with the tidal current. Or, like some do, run slow, hull speed, when you are running with the current, and run at planning speed when you are going upstream.

Harvey
SleepyC :moon
Click to expand...

I was reminded that there are situation even on fresh water where there are currents to deal with :oops: where is the smileyface for smack in the head?
I recently spent 2 weeks down in the SF Bay and Sacramento Delta. Whoa now, tied to the dock in Oldtown Sac, and the current there was better than 3 knots.

I don't have extended open ocean cruising experience but my understanding is that there are places out there where there are currents too. I do know there are tides there, so there is some kind of water movement. (Is it really jusy up and down? Or ...)

Harvey
SleepyC :moon
 
SleepyC :moon[/quote]

I don't have extended open ocean cruising experience but my understanding is that there are places out there where there are .... tides ... some kind of water movement.

Harvey
SleepyC :moon[/quote]

Harvey,
Water moves continuously.
It hardly makes sense to me to bother with the idea of an "open ocean tide" since
there is really nothing close by to use the measurement against mean sea level.

Aye.
Mark Twain used to say, "It's not what we don't know that gets into trouble. It's
what we're darn sure of that just ain't so."
 
There certainly are currents, both superficial and deep thru the oceans of the world. Generally the Northern Hemisphere has clockwise currents, and Southern Hemisphere counter clockwise currents. Many of the currents that small boats--and many ships,--deal with are superficial, and are influenced by the winds--both storms, and Tradewinds.

Some coastal areas, have significant currents--such as the PNW-where there are large bodies of water which the tide passes thru, and the currents vary with the tide. Others are like the East Coast and parts of the Gulf of Mexico--where the Gulf Stream has a fairly constant average velocity close to 4 mph. These currents have loops and back Eddys, which will often reverse--such as in the Gulf of Mexico. There are services which predict the Gulf Stream and Gulf Stream loops, so low power and sailing vessels can plan the best routs. Also Publications, such s Ocean Passages of the World, Jimmy Cornell's World Cruising Routes, and Pilot Charts show currents and the best route to take advantage or minimize the effect.

If one were plotting a trip to the Bahamas, it would be necessary to take into account direction, velocity and width of the Gulf Stream. This can mean a 15 degree or more alteration in planed course (Also, depending on boat speed).

Map of surface current velocity of Gulf Stream.

gulfstream1.jpg

Hundreds of boats go back and forth between the Channel Islands of S. Calif, including Catalina with not a single worry about the current. California Current Flows South, but is minimal in this area. There is an opposing current, often more pronounced in the winter, called the Davidson Current, which normally is not a factor, but I have seen it go up to half a knot North bound--and be an effect for a low speed boat [5 knots boat speed, 30 miles, would be a set to the North of 3 miles--significant, especially at hight before electronic navigation. (personal experience--my DR was off by 3 miles} ].

The Mississippi River (unfettered by Dams below the Illinois River) flows at an average 3 knots at New Orleans. But its velocity can reach over 6 mph--and currently is 4 miles per hour in Bel Chase, LA. I had a friend who said he saw velocity of 10 mph during a severe spring flood...
 
We just finished a 115 mile trip, averaged 17mph, burned about 25gal give or take a few gallons. Honda 90hp, 2 adults 2 kids, 2 full coolers in the cockpit with gear for overnighting. Came out to about 4.6MPG. We had a god bit of no wake zones and ran WOT a lot too on the way down, 24-28mph. We're in a heavy tidal area, sometimes it helped, sometimes it hurt. Even with a few gallon error in estimating fuel use we were between 3.8mpg-4.6mpg.

I can't say what we do at 4,200 rpm but 11kts (12.6mph) seems a little slow. I'd guess we were 20mph or a little more, but we did have 2 kids instead of 2 adults.

WOT is about 5,500 28-30 mph depending on water and weight.

Prop is a 13.75 x 15
 
Snider":29c51ton said:
4,200 with 4 adults 2 kids 16.8knts against 0.2knt tide.
Click to expand...

If this is at WOT (wide open throttle), you need to take 2 or probably 4 inches out of your prop pitch: down to 13 or even 11 from 15 inches.

4,200 rpm and WOT is really lugging the engine, badly.

Joe. :teeth :thup
 
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