Appreciate the replies!

I do understand the science thanks to Boyle et al -- this is just the first time it was noticable in any car I have owned. I did not know, however, if the engine management computer was allowing the engine to take advantage of the denser air, or that it had such a significant effect. Lee's stats are astonishing (to me.) If I go back to my carburetor and big block days, I swear I got no such effect.

I'm off to find that friend with the 99 GS400 who I could only barely out run in the heat a few weeks ago. We'll see if O2 burned with rice creates the same effect!

Thanks again,
Greg