I was a bit surprised the other day when someone tried to tell me humid air has more O2 than dry air and thus car runs less hp in dry air. I always thought and I am not far out of chemistry days-the more humid means more H2O is in the air and less PO2-actually I am positive of this-so was this guy just wrong or is there some component of humid air and cars that I am missing?

 

They are completely wrong.
Dry cold air is the most dense and makes the most HP.

 

That is what I was sure of but second guess when a supposed "expert" in cars tells me otherwise-sad thing was this is the fool that ran my dynojet disaster day-man the guy was a loon-really sad thing was he said he worked on all types of cars-including new bimmers-only god knows what a mess he would make of a new bimmer yikes