Fuel economy on 310 DA

[fsudelt]

I have a 07 310 DA w/ 6.2 V Drives. Anyone else have same boat or similar setup? Wondering what your best cruising speed is and gph? Right now from my smartcraft I'm coming up with around 22-24 mph, 3650-3700 RPM's, for about 25 gph. Don't know if this sounds in range or not, or if on a long haul it would be more efficient to cruise faster and give up a little on the gph. Thanks for any input out there.

p.s.- I think the 25 gph that smartcraft is showing might be on the high side because when I fill up I'm not using quite as much as it's saying if I calculate the trip time. Is there any other easy way to measure?

Brian

 

[stephane]

Mine is not the same years and engine but maybe it could help you a litle

I cruise at about 27-28 mph for about the same 25 gph but my RPM is a way lower at 3100. the lowest speed cruise I could hold is 25 mph but it is not realy good there

 

[Alex F]

Right now from my smartcraft I'm coming up with around 22-24 mph, 3650-3700 RPM's, for about 25 gph.
Brian

Brian,
These numbers look similar to mine, except I'm doing 24-25MPH at those RPMs in normal seas. May be this is b/c our boats are somewhat different.

 

[Vince_nj1]

Google SeaRay 310 test and you will find this.

http://www.boatingmag.com/article.asp?section_id=4&article_id=775&page_number=2

 

[berth control]

Google SeaRay 310 test and you will find this.

http://www.boatingmag.com/article.asp?section_id=4&article_id=775&page_number=2

Nice link Vince:thumbsup:

 

[stephane]

The link have the 5.0 liter and is realy slow pig in gaz less 6 hours with 200 gallon of gaz

 

[dpmulvey]

I have the 330 with 6.2's. I burn about 22GPH at 22knots at ~3650. She is more comfortable at 4K, however, I need some more ER insulation due to the noise factor and at 4K the fuel consumption increases as well.

I don't know about the 310, however, the 330 is grossly undertabbed causing them to squat terribly. I verified this with Bennett Tabs and the recommendation they give as the textbook answer is to extend the current tabs from 9 to 15 inches. Others have reported to Bennett their ability to plane at lower RPMs without a signifigant loss in speed or bow rise.

Are you running 3 or 4 blade props and what is your WOT RPM. Four blades are far more effecient and will serve to raise the arse of the boat underway with less tab. WRT your WOT, the 6.2 is a different animal than the 7.4 in an inboard application.

I have the engine specs in front of me. Other than the WOT RPM, the 6.2L inboard with a 4600 to 5000 WOT Range and 6.2L I/O with a 4800 to 5200 WOT range spec as exactly the same engine. The problem with that is that you will never get the engine to full stride. I found the weak link to be the maximum transmission RPM on the V drives to be 5000 RPMs. IF you are say turning 4600 RPM at WOT, you are actually robbing your engine of 600 RPMs of top end power as well as laboring them in the midrange.

HTH

 

[fsudelt]

Google SeaRay 310 test and you will find this.

http://www.boatingmag.com/article.asp?section_id=4&article_id=775&page_number=2

Looks like from that link i'm about in line, maybe actually doing alittle better than what's shown in that test (because I have the larger 6.2's and usually always run on a full tank). I usually run at about 3600-3700 rpm, but from that chart it might be more economical especially on longer trips to actually run closer to 4000 rpms? Even though I'd be burning more fuel I'd pick up some mph and increase my cruising range it seems. Thanks for all the posts!