Rusty - Both of the cars you mentioned are marketed with their economy in 30s mpg. The difference should NOT be THAT immense.
Seriously, 70mpg is revolutionary, it kills the gist of the production of low consumption hybrids.
I'm pretty sure you're mistaken..maybe it's 70 kilometers per gallon, because you've mentioned the distance in kilometers in your above post.
One more thing, hi octane means better combustion, it in no way guarantees better Economy.