Very interesting SAE LT1 document!
 

I found the SAE rating for the Camaro, and as we all know that they just used the certification from the vette as this test was dated May of 2013. According to this document, the Vette made 458.38 hp and 457.67 tq. But GM certified both at 455, and that is what the Camaro is certified at. But if you look at the bottom of the document, it shows that number could jump.

I could be reading it wrong but I read the bottom to mean that GM promises that it will make at least 98% of what it is rated at. How does this equal leaving the door open for more power? I'm not saying that they won't have more power in the future, but I'm just not getting that from this document.

Not the same, but they were tested at the same time. The engine has to be rated with the vehicles intake, exhaust, and belt driven accessories.

C7 LT1 results:
http://standards.sae.org/cpgm2_14lt1corv/

455hp / 460tq

I was thinking if they are allowed a 2% under the rated power, then they would be allowed 2% over in these engines as what we are seeing.

I read it as the engines have to produce a minimum amount of power and torque, but there is no maximum limit to how much power the engines must make. I think it would be a mistake to assume that a 98% guaranteed floor = a 102% ceiling to how much power is made.

I'm not saying it is, but this document does leave the door open for people to declare that underrated engines are alive and well. I personally don't see the benefit to a manufacturer to underrate an engine.

It assures no manufacturer will claim a HP number that the customer will never expect to see lower than 2% less. It is the margin that assures a manufacturer won't bring in a ringer to get a good certified number and then build less engines in production.

It is our protection that with 455 advertised you CANNOT see less than 446 in a customer's car.

Guaranteed minimums.....but they are free to make them 460HP, 470HP,etc.

Horray for us ;)1

I think what I find most shocking here is the date. Two and a half years ago! That's a long time!