I have a 2005 Aveo sedan 5spd at 9500 miles and am currently getting 32.07 mpg. I got this car from a guy who repossessed it so there are things that are aftermarket on it (tires and rims). Not to mention there isn't a manual so I'm looking for a manual, do they sell those at a chevy dealer?
I love the car, lots of pep and it never gets dull for me, only on long ass road trips. Most of my driving is mixed between city/highway.
What I find surprising is that castrol improves fuel economy, I'm going to have to start asking around places to see if they use that oil (i don't know how to change it myself, but I am willing to learn), because like someone else said, you get an improvement of 8 mpg and that is a God send!