Run at WOT, or lower?

[craqpot]

Under typical operating conditions my WOT of 5800 is in the middle of the manufacturer's specified range.<br />(2003 Merc 50hp EFI 4-stroke). <br /><br />Is it significantly less engine wear and tear per mile to run on plane at, say, 4400RPM or 5200RPM instead of 5800RPM?

 

[Solittle]

Re: Run at WOT, or lower?

Outboards are designed to be run at WOT all day long if you wish. If my memory serves me right OMC used to recommend that the "best" rpm for performance and economy was WOT less 10-15%. My experience tells me that each boat has a sweet spot for a given load & hull. You can almost feel it. For example my 1987 110s have a recommended WOT of 5500 rpm but seem to like 45-4800.

 

[roscoe]

Re: Run at WOT, or lower?

2 Strokes usually get their best fuel milage at approx 2/3 throttle. <br /><br />4 strokes ?? probably similar.

 

[cobra 3.0]

Re: Run at WOT, or lower?

Smaller engines are continuously run at WOT with no ill effects. Your 50 won't suffer at WOT. It will use less gas at about 2/3 throttle...just enough to keep the boat on plane.

 

[craqpot]

Re: Run at WOT, or lower?

Thanks. Great answers.