Posted by TK1 on 02/06/19 - 9:59 AM
#1
I am a little confused from reading some forum threads related to HP. One mentioned a 90 HP yielding 112 HP. Is this similar to a car engine HP / to the rear wheels HP?
Posted by Phil T on 02/06/19 - 12:14 PM
#2
The thread was referring to an E-TEC 90HO. The HO in the model name indicates "high output".
You will note in that same thread the 90HO engine is a V4 block while the E-TEC 90 is an inline 3 cylinder. The engine displacement is also different.
At one time, engine hp was rated at the prop. That is no longer the case.
Edited by Phil T on 02/06/19 - 12:15 PM
Posted by Finnegan on 02/16/19 - 10:03 AM
#3
I think what Phil meant to say is that at one time, prior to 1984, outboard engine HP was rated at the powerhead. Now all ratings are at the propeller.
Since 1990 or so, engine manufacturers have taken advantage of the BIA 10%HP rating rule, on the upside, to sell higher performance engines and still use a lower HP rating to get around BIA hull HP rating rules, etc. Examples are the Mercury XS and ProXS names, Evinrude HO and Yamaha V-Max. All put out more power than the number indicates. As an example, a Mercury 150 ProXS actually puts out about 170HP, but they can get away with putting in on a boat rated for 150HP. So if you want to slightly overpower a hull, using these designated engines is one way to do it and not have insurance or other problems. These engines are now commonly used in the bass boat market, and have been for years.