2010 S, Stock except a K&N air filter. The "Computer" on the Cube says my average is 36.9 MPG. I write down the miles/fuel at the pump and the average I calculated in 6 fill ups was 36.7.
Now let me explain my driving habits:
I drive to work 25 miles one way. I have 6 stops on the trip (maybe a couple more depending on lights at end of trip). So I consider my drive to and from work 90% highway miles. I take country roads 3/4 of the way and a highway the last 1/4. I leave about 6am. Most of the year it is dark and have to watch out for a lot of deer in/near the road. There is hardly anyone ever on the road. The 3/4 of the way on the country roads, I drive mostly 45 mph to work and 50 mph on my way home (more anxious to get home). The 1/4 of highway road, I drive 50-55 mph, depending on traffic behind me. The rest of my non-work trip driving is short drives around town running errands.
The Cube "computer" say my average speed
is 30 mph. Considering the above, that is probably true. I know the "Live" MPG while driving seems wacky. Going 45 with 1500 RPMs I've seen it say 60 MPG. Then it will jump all over the map to say 40s. That being said, I still believe the 36.9 MPG to be pretty accurate being the average of my hand calculation comes up the same.
So the moral of the story is, if you have the luxury of leaving for work a little early and open roads with no disgruntled drivers behind you
and mosey along at 45 MPH, you could get some more MPG.