Best cruising speed for a 260DA?

[EricW]

Based on my experience with my 260DA, at 3500 RPM he is not on plane any longer so the 19 mph makes sense to me.

That surprises me. Although 3500 is likely not the best cruise speed, I would think 3500 should still keep the boat cleanly on plane, with speeds in the low/mid 20s.

 

[JohnEGraham]

I have a 250DA 98 and run 22 MPH at 3000 RPM. Thats' pretty full of crap an 2 people

 

[Dave S]

That surprises me. Although 3500 is likely not the best cruise speed, I would think 3500 should still keep the boat cleanly on plane, with speeds in the low/mid 20s.

I referenced these numbers earlier in this posting, but here are my numbers (taken mainly for fuel burn statistics)

Speed/ RPM / Fuel Flow/Consumption

07.7/ 1540/ 02.32/ .36
09.7/ 2410/ 05.86/ .69
15.7/ 3120/ 10.78/ .78
25.3/ 3570/ 12.08/ .55
27.9/ 3950/ 13.37/ .55
31.7/ 4380/ 17.50/ .62
35.2/ 4680/ 20.24/ .65

Notice the huge speed difference between 3120 rpm and 3570 rpm. Even though the speed shows at 25.3 mph at 3570 rpm there is a reason for that. I had throttled back to 3570 after planing at 4000 rpm and the boat was barely on plane at 3570 rpms. Drop the rpms a little further and the boat drops off plane like a rock. And as you come up thru the RPM range you are only getting 15.7 mph at 3120 so you will not be much faster than that at 3500 rpm. The boat doesn't really plane out fully until it hits 3800 or 3900 rpms. That's why I typlically have to take my boat up to 4000 rpm when planing and then throttle it back to a reasonable cruising rpm which is usually around 3800 rpm.

Dave

 

[EricW]

I'm with you now Dave. Your data chart makes perfect sense. It looks like 3500 is the breakover RPM for the 260 with the 350 Mag/Bravo III. I guess its all about power to weight ratio and prop pitch/gearing.

 

[medic3538]

3750 RPM - Bravo II drive (big wheel) 24 - 27 MPH at 11.8 - 13.8 GPH depending on fuel, water, people on board, etc., etc. Engine gettting built up and chomping at the bit to get her back.

 

[billnpat]

Based on my experience with my 260DA, at 3500 RPM he is not on plane any longer so the 19 mph makes sense to me.

What does it take RPM's to get on plane with the 260 DA???

 

[Dave S]

What does it take RPM's to get on plane with the 260 DA???

I mention it in my last post.

"The boat doesn't really plane out fully until it hits 3800 or 3900 rpms. That's why I typlically have to take my boat up to 4000 rpm when planing and then throttle it back to a reasonable cruising rpm which is usually around 3800 rpm."

 

[billnpat]

I mention it in my last post.

"The boat doesn't really plane out fully until it hits 3800 or 3900 rpms. That's why I typlically have to take my boat up to 4000 rpm when planing and then throttle it back to a reasonable cruising rpm which is usually around 3800 rpm."

...IM GOOD AT 3200-3400 on my 310.:thumbsup: planning,cruising,gas usage :thumbsup:

 

[magster65]

...IM GOOD AT 3200-3400 on my 310.:thumbsup: planning,cruising,gas usage :thumbsup:

I can cruise that speed too but it's a much better ride at 3500 rpm @ 30 mph (20.5 gph). The optional 2 x 5.0 mpi power is great in the 290. With a fresh hull it did 45.9 mph at 4700 rpm with 2 people / half load. You don't need that kind of top speed in a boat like this but the fast cruise is nice... if you want it. I still putt most of the time though...
What does a 260 burn at 30 mph?

 

[Dave S]

17.5 gph.......see my burn chart above.

 

[magster65]

17.5 gph.......see my burn chart above.

Yeah... that's at 31.7 so it's probably in the 15 gph range at 30... interesting. That's about the same as skibums 496 260.
2 mpg at 30 mph... I get 1.5... lol that sounds so bad!

 

[skibum]

I can tell you one thing, I don't care what the numbers "read" via GPS & Smartcraft, I never get 2 MPG when I look at actual distance vs. fuel burned after a trip.

On Saturday the 4th, I ran it from Millers Island to Brown's Cove off of Little Round Bay. It is approximately 26 miles. There was a small craft advisory, 10-15 knot winds out of the west, and steady 1-1/2' waves for most of the trip. I was fairly close to the western shore, so I had decent protection from the wind. Going by the mouths of the Patapsco and Magothy was interesting, though. Gave Mr Westbound wind a chance to kick up some steady 2 footers for a couple of miles. The last 6 miles were on a fairly calm river almost directly into the wind. I had a 300lb buddy of mine on board, a full water tank, 3/4 of a holding tank, about 200 lbs of stuff like food, drinks, luggage, and my bigger toolbox. It took about an hour and 25 minutes. I had 5/8 of a tank when I left, and 3/8 when I got there. That's about 21 gallons by the gauge.

I rarely let the engine run the same RPM for longer than 5-10 minutes, so the RPMs were mostly in the 3350 to 3550 range. As you can tell, these aren't large changes, just minor ones to give the engine some "variety" during the trip. For this trip, most of it was closer to 3500. I was seeing fuel burn numbers between 14.6 and 15.1 on the display. I never looked at the GPS for speed. Its a little teeny tiny number on the top corner, and the polarization of my sunglasses makes it impossible to read unless I sit down and lean over. I just never got around to it. There wasn't much in traffic out there, so I actually did get to hold a pretty steady course. All the recreational boaters were kept away by the SCA, and the commercial boats were all in port for the holiday so it was a nice day to be out. I passed about 5 CG vessels along the way and was glad to see that they took the day off. If they needed to do any safety inspections, it would have had to be me as they had no other choices.

The moral of the story: I'm lucky if I see 1.7 MPG on most days. For most trips, its 1.2 to 1.5 MPG. I attibute that to never really travelling in an exactly straight line, tides, winds, waves, etc.. I know I could get closed to 2 MPG on a lake, with no wind, no other boats, mostly empty tanks, and with just me on board.

 

[Dave S]

If folks wish to run at trawler speed they will get infinitely better mileage than planing speeds or if you are foolish enough to run just below planing speed you will get infinitely poorer mpg.....the same goes for WOT. All of my numbers show just that.

Dave

 

[jollymonsrv]

new to this boat i am curious to hear other peoples opinions also, especially about economical speeds etc.
i feel my boats comfortable cruise speed is about 3500 rpm.

my 04 350/br3 cruises 3500-3600 20 mph 12/12.5 gph all day long OnPlane....And the wife is happy Salt water Boston Harbor:smt038

 

[magster65]

I can tell you one thing, I don't care what the numbers "read" via GPS & Smartcraft, I never get 2 MPG when I look at actual distance vs. fuel burned after a trip.

I rarely let the engine run the same RPM for longer than 5-10 minutes, so the RPMs were mostly in the 3350 to 3550 range.

The moral of the story: I'm lucky if I see 1.7 MPG on most days. For most trips, its 1.2 to 1.5 MPG. I attibute that to never really travelling in an exactly straight line, tides, winds, waves, etc.. I know I could get closed to 2 MPG on a lake, with no wind, no other boats, mostly empty tanks, and with just me on board.

True... it's very difficult to verify the exact fuel burn vs. speed with all the variables that occur during an outing. I never go 'in between' planing or disp. speed as an attempt to keep the mpg as good as possible. This is my first boat with twins so I've kept a close eye on it. What I've found is the average usage is right at my consumption at cruise... about 1.4 mpg. The non-accountable fuel used warming up, idling around and docking is made up for when I'm putting at disp. speeds.
This also points out something else... whatever boats you compare... for fuel burned per outing, the way you use your boat is used is most important when it comes to dollars per mile. Working with the tides and putting a bit more can save lots of fuel throughout a season.
So... on a similar topic... hurry up and find out your w.o.t. speed in ideal conditions! I wanna' know what a 496 260 does! I think it'll go 50... high 40's for sure!

 

[mooney]

(The '99-'04s are about 1100 lbs lighter (depending on options) than the '05-'08s. I cruise at 3500 RPMs and 25-26 knots (30MPH)consistently. I have 24" pitch props on the BravoIII )

same boat
I almost always cruise at 3 grand and Im doing 24/27.mph (gps) depending on conditions and trim ........wot 2 people,beginning of season,43mph

 

[JaydubyaSR190]

I notice this is an older thread but hoping someone will see it and give me some insight. I have a 99 260DA with the 5.7 and a Bravo ii out drive. Currently running an 18.75 by 17 prop. I'm getting 4200 rpm at WOT which gets me about 32 miles per hour by GPS. I usually cruise at 3800-4000. From what I can tell on this thread I'm getting optimal rpm to speed ratio?

 

[Stray Current]

I didn’t run my boat much after I got it last year, but I seem to remember 3700-3850 being most efficient cruise at right at 2.0 mpg 24-27 mph.

It’s the heavier 05-08 with arch, genset 6.2 horizon. 20 pitch props, and 2.0:1 gears i believe.

It’ had a full tuneup, has a fresh clean bottom and all new Simrad gear installed now. Looking forward to see my new actual gps derived numbers very soon.

 

[Groucho]

Yep. 26p props and a 2:20 ratio.

The pull matches the published torque curves extremely well. At 4000 RPMs I have to hang on to the wheel pretty good just to stay in position in front of the seat, at 4500, I have to sit down or cut back on the throttle.

I generally cruise "comfortable". 90% of the time, I run around at 3300-3400 RPM doing somewhere between 24 and 27. I could probably live with a smaller engine as I rarely use this one to its full potential. That being said, I wouldn't give it up. There have been times where I DID need it, and I was glad that it was there...

I had a single 496 in my prior 2006 290 DA. It is a SWEET engine. I had over 600 hours and not one hiccup. I think it is one of the best engines to hit the market....