I'm making a 2 week loop from NJ to Devil's Tower, Deadwood, Yellowstone and Pikes Peak then back. My Sport Tourer got 50 mpg with 6+ gal tank so never had to worry about fuel. I have ~4k on the RT and I'm only getting ~30 mpg with lots of 70+ mph miles. I figure that's not going to improve when in the plains.

Do I need to carry a roto-pak 2gal or am I being paranoid?