Awesome looking cars but reads some reviews...They are **** with a capital S. Honestly probably the worst car Nissan has ever made.
Here is some light reading
http://www.caranddriver.com/reviews/2011-nissan-murano-crosscabriolet-first-drive-reviews
I have the same truck same year in the crew cab model and my truck (despite 3 different brands of rotors) did this until I bought OE rotors from the dealer. Don't know why it made it go away but it did. Maybe these other guys can give you some better information.
Look at the VW jetta TDI models. I had one and got 50mpg on the highway if I kept it under 80mph. I would get low 40s in the city. The down side is that it was a 5 speed and didn't have a ton of get up and go. The TDI will be what I buy after my new accord craps out.