I'll cut and paste what I just read here, what do you guys think?

""i have a 2004 aveo, i was getting poor gas mileage and performance.
i decided to do my own maintenance. i change spark plugs from acdelco to
just plain autolite copper core part#3923, i changed my factory air filter
to a k&n easy fit filter part# 332320, just drop it in and throw away your old filer,
dont put oil on the filter just wash it off each oil change when it gets dirty.
just use plain 5w-30 oil. not synthetic.put 32 psi in tires at night. im now getting
30mpg city and 45mpg hwy. i also have beaten the following cars. 3.8l grand prix,
2.0 eclips, 1.6 civic, 1.6 mini cooper, v6 mustang. this car is so fast i cant beileve it.
im so confident this will work for your aveo i put my email public, gm will flip out
when they find out we all figured out the aveo's hidden secret power.
its just a deawoo lanos, and that car got 40mpg in 1999. guess what?
it had copper spark plugs from the factory not platinum.
thats why the aveo has so many performance complaints, lack of spark and air.
copper is a better spark than platinum they just need to be replaced every other oil
change. gm has riped us off all this time by using thick paper air filters and
platinum spark plugs. any car with a 1.6 engine can get 30mpg city. they know
that, but they want to keep everybody in the dark. try this out, i guarantee you
wont be disappointed. pass it on to all aveo owners and fansites.any questions
email me at tony565565@gmail.com ""

Seems worth a try..