Hi, We are living in New Zealand and have traveled and loved visiting the beautifuly diverse USA many times! we have often wondered about hiring an RV..now our kids are 5 and 8..and we are heading back to Denver for a conference (end of May)..we actually arrive in the US on april 25th and need to be in Denver around 15th May , then home shortly after..we have seen a deal to take an RV from Chicago to Denver for $39 per day including one way fee, generator and mileage of 2500..so that seems quite reasonable compared to renting one. We don't know the size until we get there... I have a few questions for you seasoned Rv ers..roughly how much is the petrol/Diesel cost per day/tank? And any suggestions on route? We really enjoy the National parks and last year visited Rocky mountain, Black Canyon of the Guinnson, Mesa Verde and Grand Canyon..this time we were thinking to either come in to Denver up the top through Dakota way or alternatively via New Mexico..or as another option, heading over to Great Smokey and then back over to Denver (prob least likely to do this one as a bit far maybe?) the other thing we are unsure about is camping in the National parks where there have no power hook ups..I take it this means you have no ability to use the shower in the RV or toilet?? As you can see we are really new to this! so if you can direct us to any books on basic use of Rvs or websites..that would be great..thanks alot..