04 Chevy Aveo

[Lola]

I put the Underdrive Crank Pulley on my 04' about 40K ago. Made a little difference. Slows the accessories down a bit, frees up a tiny amount of power and fuel mileage. I got it from a Vender on here. Depending on where you live and the smog police.... There is another tiny bit of potential by taking pressure off the engine's exhaust side if you cut out the muffler and replace it with a 7$ section of straight Napa pipe and gutting the rear cat. Also, the hot coolant line that runs through the throttle body could be re-routed around it to help provide colder (non heated) air and the EGR could be correctly removed for power and mileage gains, but that takes homework. But all that is after a full blown tune up/clean up and making sure the thing runs like a champ. Their's a few threads on here about headers and air intakes as well... Running full synthetics in everything to free up friction is also a proven way to make numbers better.