HCHII lean burn tuning?

[HybridGates]

So I thought the HCHII had a lean burn mode, however it seems it doesnt. And im guessing that it can be safely tuned to run a leaner mixture without ping or and sort of issues, but has anyone done it?

Im just thinking of ways to get my HCHII Mpg up because its only getting around 40mph on highway and some 38 in town. Something the prius has much over in the civic hybrid, or does the prius exaggerate mpg? Eitherway, if there is some other way to get mpg safely up please tell me.

I bought A BG 44k cleaner that will hopefully clean out egr valves and such. Or is there some order I am supposed to use their products?