i think the average lose is about 20% from flywheel to wheels. Just Google "horsepower lose from flywheel to drivewheels" and u will get an answer.
Some1 who knows better will correct me.

 

That is the number at the crank not at the wheels maybe around 120-125hp more or less with auto could loose more.

 

Thanks! That's exactly where I found it on my 2000 accord.

 

typically there is about 14-18% parasitic loss for most cars, manuals are better at minimizing this than autos.

129 whp for a brand new engine.

then if you take into account 150k miles (average for cars this age) take another 10% of that

116 whp accounting for age

then if you live at any altitude above sea level then you loose ~3% per every 1000 feet.

I live at 5000 feat so I loose 15%

So I'd be lucky to get 100 whp out of my 02 accord.

 

I know this thread is old, but posting for information only. There is a code right on the block. See the pictures below -