I suppose it's not more complicated than an LPG system in a car, which fires up on gasoline and switches to gas only after warm-up. My Uber today was a Corolla

I suppose it's not more complicated than an LPG system in a car, which fires up on gasoline and switches to gas only after warm-up. My Uber today was a Corolla hybrid and at one point I heard the telltale clunk of the LPG system engaging. Apparently you can have that on a hybrid as well.