Why would just doing crude+condensates only be considered wrong anyway as far as peak detection goes ?

NGL's do not provide anything close to the range of products derived from crude oil so they are not directly equivalent to crude and neither is natural gas for that matter.

I even question including the very heavy high sulfur crudes and tar sands without weighting. The production and refining of these is far more expensive and energy intensive than regular crudes and overall they are not a replacement for light sweet crude.

In short the key is the production of the types of crude we have built our economy around which is centralized on light sweet crude and thus the economic impact of peak oil which is what we are really interested in will follow the availability of the lighter sweeter oils.

The interesting thing to look at is how the main depressive shock started in the 1970s and then slowed down into the 1990's. For this model to truly make sense, people should buy into the fact that significant changes in oil usage occurred spanning the two decades. Clearly, up to the 1970s, consumers used oil like it was water, applying it to all sorts of what we would consider now incredibly wasteful actions. But then the conservation movement woke up, and the USA subconsciously lead the way when they realized their own supply was petering out. So the key is to buy into the possibility of that 40% dip in extraction rate from the available reserves over two decades.

I don't think NYMEX believes the EIA:

$88.50

Arkansaw of Samuel L Clemens