A race between the Godzilla-like Cadillac Escalade SUV and the gazelle of a Nissan GT-R to see which could sprint to 62 mpg the fastest doesn't seem like it would even be a fair fight. Yet, the two cars agreed to meet on an isolated country road to see which would leave the other choking on its dust.

Cadillac took one important measure before the race to help level the playing field. They had?