Horse power ratings

[Tom Brown]

An aquaintance of mine tells me Mercury rates stern drives at the prop these days. When did they start doing that? Are all Bravo engine packages rated at the prop?

[Pro Max]

that is not true,

[Greg_Moss]

An HP 500 is rated at 470 at the prop. You loose a small persent of HP per set of gears. On a stern drive there is 2-90* gearsets. I believe all sterndrives are propshaft rated now. I'm not sure about Volvo but am about Mercruiser. The engine package HP is the rated power at the prop it's the same as the way outboards are rated.

[Pro Max]

When you see bost evaluations you will notice on a 525 it shows 500hp at the prop. A 525 package with an XR drive makes 500 at the prop.