MPG testing

[datechboss101]

I am not new to fuelly, as I used the app before but suddenly stopped. However, I am using a different vehicle, just pure highway driving on the Florida Turnpike for a good 230+miles. Although I am doing lots of highway driving, I am practicing proper fuel efficient techniques: Using Cruise Control @ posted speed limit (70 MPH), A/C @ speed 3 or even lower, not doing WOT, yet I am not getting the advertised MPG of 33 HWY that Nissan claim's. Florida HWY Patrol gave me a go ahead to drive at the minimum speed on the turnpike which 55 MPH. Also I will be using Fuelly, some excel spreadsheets, etc., to make sure I am getting accurate MPGs for this SUV.