Understand that the initial market for this vehicle would be fleets that have dedicated routing, with central refuelling or whatever. They have a defined range. The concept of only adding a partial range of gasoline is to encourage the use of the natural gas on that vehicle, maximizing the natural gas tank volume to provide that customer the ability to reap the benefits of natural gas use. Gasoline is there for range anxiety; you give it to give some range.
On March 8th, 2012. See this statement in context.