I posted this on Camaro5, thought you guys might find it interesting as well.

I was talking Camaros with a guy that has an office in the building I work in. He has a '10 Victory Red Camaro LS as his daily driver. He was almost apologetic about “only” having the V6. So I pointed out to him that the big old heavy, thirsty 396 big block in my 67 was rated at 325 bhp GROSS, while his V6 is rated at 304 bhp NET. If you approximate the difference his V6 is making more power AND gets 29 MPG highway.

So I did a little checking:

“SAE Gross Horsepower
This is the old process that American manufacturers used as a guide for rating their cars. It was in place until 1971. SAE gross also measures horsepower at the flywheel, but with no accessories to bog it down. This is the bare engine with nothing but the absolute essentials attached to it; little more than a carb, fuel pump, oil pump, and water pump. Because the test equipment on the engine is not the same as in SAE net, it is impossible to provide a mathematical calculation between SAE net and SAE gross. As a general rule, however, SAE net tends to be approximately 80% of the value of SAE gross. SAE J245 and J1995 define this measurement.”


So using that to approximate numbers for comparison:

LLT DI V6---304 Net----~365 Gross
L-35 396---~260 Net-----325 Gross

To further that:
LS3 V8-------426 Net---~512 Gross
L99 V8-------400 Net---~480 Gross

Even the hottest big blocks of the ’67-‘69 (without including the way under rated ZL-1’s):
L71 427-----~348 Net----435 Gross
L88 427-----~348 Net----435 Gross

Or the somewhat under rated 70 454 rated at 450 bhp but thought to really produce about 500 bhp:
LS-6 454----~400 Net----~500 Gross

Technology can be a wonderful thing sometimes! I think he felt a little better about "only" having the V6!

Thanks for this, Mike.
The 80% rule (approx.) is a handy piece of info to carry around in your head.