Horrible mpg or is it normal

I have an 2009 rzr 800s with 27" roctanes and exhaust and fuel controller I went riding this weekend at Carolina adventure world in South Carolina It was my first big ride so when I filled the Rzr back up and figured out the miles per gallon it was 5.5 I know the 2009-2010 get worse milage but is it that bad? We have a trip planned for Windrock at the end of the month and its got me worried that I’ll have to pack some fuel on the trip and that doesn’t seem to safe any input would be great to be able to get better MPG thanks