old merc perf bulletins

[phatmanmike]

anybody have an old inline 6 performance reports such as those found on the evinrude or yamaha websites? do these even exist? you know, the ones showing the motor on a certain boat showing RPM vs MPG vs GPH etc etc etc????? just thought id ask

 

[achris]

Re: old merc perf bulletins

If you're interested in GPH, then this is the rough formula<br /><br />At WOT, (UK)GPH=HP/10. (your 115 will drink about 14 (US)GPH)<br /><br />1 US gallon = 0.83 UK gallons<br /><br />Just work out the MPG at WOT and scale it for lesser speeds. From your previous post I think you're probably get about 47mph, so that would give you about 3.4 MPG. So, for your 30 mile trip, I'd expect to use around 9 gallons. Since you weren't running a WOT you'll use a bit more, maybe another couple gallons. 2 strokes are at maximum fuel economy at WOT.<br /><br />Chris.............

 

[JasonJ]

Re: old merc perf bulletins

Achris, not to be argumentative, and I cannot vouch for all 2 strokes, I can assure you that Merc inline six motors, WOT, and max fuel economy do not happen in this plane of existance. 3800-4200 is where it happens for the most part, if propped properly. Any faster and that thing just tears through gas like Rosie Odonell through a stack of ho-hos. The speed, distance covered, and fuel usage ratios get warped dramatically when compared to figures gathered when the motor is in the sweet spot rpm-wise. Through my own personal experience with different motors, it has always held true that about 3/4 throttle gives you best economy. Individual experimentation is required, no two boats/loads/user is alike.

 

[ZmOz]

Re: old merc perf bulletins

Originally posted by achris:<br /> If you're interested in GPH, then this is the rough formula<br /><br />At WOT, (UK)GPH=HP/10. (your 115 will drink about 14 (US)GPH)<br /><br />1 US gallon = 0.83 UK gallons<br />

That might work for other motors, but for an inline 6 it's way off. Using that formula I get about 18 GPH for my 1500. I get about 2mpg at WOT which gets me to 50mph. That's 50 miles @ 2mpg, so 25 gallons per hour. Good lord...that's $0.92 a minute!