Not positive on the killing of the motor part, you'll have to wait for a tech to come along to confirm that. But if i'm remembering correctly it will SERIOUSLY screw things up.
It will most definitely void the warranty tho.
And the fine's for running it in your truck, well here in NC its upwards of $15,000 or more.
Not worth it if you ask me. Considering there's no real benefit from it, and it definitely is not that much cheaper that it'd be worth the fine amount.