150 HP e dintorni, qualè il più silenzioso? [pag. 14]

Grazie, capitan vagabondo!

dovere...

A distanza di un anno esatto... si è capito quale 150HP è più silenzioso? Mi pare di no.

Volevi una tabellina? I valori sono espressi in dB-spl, sono tratti da questo sito:

https://www.ausfish.com.au/vforum/showthread.php?t=128225

Outboard noise levels

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This is quite dull, but does reinforce my thoughts way back about the Engine noise in a 2 stroke V 4 stroke, and the fact that at idle, a 4 stroke wins hands down, but after that it changes to a very different result, this is a cut and paste from a US site and refers only to Mph, test conducted on identical Boats with 150HP Outboards.

Powerboat Reports has published test results comparing six different 150-HP engines:

Four-Stroke
Mercury Verado 150
Suzuki DF150
Yamaha F150
Honda BF150
Two-Stroke
Mercury Optimax 150
Evinrude E-TEC 150
In terms of sound at idle speed of 1,000-RPM, the quietest motors:
dB-SPL / Motor
63.5 -- Suzuki
64.0 -- Verado
65.5 -- Yamaha
66.5 -- Honda
69.0 -- E-TEC
72.0 -- Optimax
However, pump the speed up to 1,500-RPM, a typical No-Wake speed, and the order changes to
dB-SPL / Motor
70.0 -- Yamaha
70.5 -- Honda
71.0 -- Verado
71.5 -- Suzuki
75.0 -- E-TEC
79.0 -- Optimax
Jump ahead to cruising speed, and the order changes again. This time we are going to look at boat speed, not engine speed. This helps the two-strokes because they won't be running the engine quite as fast. Now the results are:
dB-SPL / Motor / Mph
84.0 -- E-TEC -- 29-MPH
84.0 -- Yamaha -- 27.9-MPH
84.5 -- Honda -- 27.6-MPH
87.0 -- Verado -- 27.8-MPH
89.5 -- OptiMax -- 27.7-MPH
90.5 -- Suzuki -- 30.3-MPH
At wide open throttle, the ranking changes some more. Again we compare at boat speed not engine speed:
dB-SPL / Motor / Mph
92.5 -- Honda -- 42.9-MPH
96.0 -- Verado --45.1-MPH
97.5 -- E-TEC -- 48.8-MPH
99.0 -- Suzuki -- 44.0-MPH
101.8 -- OptiMax -- 45.0-MPH
102.0 - Yamaha -- 45.3-MPH
THE SPIN
What surprises me in these results is the Verado. It had been unofficially crowned the ultra-quiet outboard. The 150-HP apparently does not live up to the big six-cylinder Verado reputation. It comes in at second, third, and fourth at these various speeds.
The big shock for me was the first-place to the E-TEC at cruising speed. I give it the nod over the Honda because it is going faster. I wonder if that is a typo? If it is a mistake, it puts the Honda into overall first-place in sound level. That BF150 is one quiet motor. Of course, it is also the slowest motor--you can't have everything.
Poor Yamaha--their F150 makes more racket than the OptiMax, an engine just about universally considered to be an old-fashioned noisy outboard. The F150 runs quietly until you pour the coal to it, I guess. Well, this is just a smidgen of the data presented by Powerboat Reports. Sound has become a big item in outboards. Folks want them to be quieter. The OptiMax did quite well in all the other categories. If this new OptiMax The Next Generation (OTNG) motor can quiet the sound level down, Mercury will have a potent motor to go against the four-strokes and E-TEC. Until then, if you want a quiet 150-HP outboard, get a ...well, you pick the winner!