Hey guys! Just bought a 2012 Chevy Cruze Eco today! I'm hoping I can actually get ~40MPG since according to Fuelly its about the only car that comes close to actually getting 40! My first mod was LED overhead lights. I'll get some pictures up soon!
Welcome to CruzeTalk and congrats on your ECO. Manual or Automatic? The manuals will easily exceed 40 MPG if even half of your daily drive is "highway". The automatics will also exceed 40 mpg but it's not as easy.
As most members have stated/found out, the engine usually takes ~4,000 miles to properly break in, and then if you bought the manual, you can easily exceed the claimed 40mpg, as most members here usually average between 45-55mpg.