Hello, I own a 2007 Aveo Ls. There was $57K miles when I purchased it in 2013. The acceleration and gas mileage sucked. The acceleration problem started getting worse. I went to one mechanic, he thought the transmission may be going bad. Went to another mechanic and was told the Catalytic Converter was going bad. I had it removed in 2015. The cost was under $150 and worth every penny. Now it is straight pipe with a light chirping sound when I accelerate. The 5-speed over drive is nice when getting on the expressway. I can fill up the tank from a quarter of a tank, pay $2.05 a gallon and spend between $15-$17 on Monday. I drive 18 miles one way to work, rolling with traffic on the expressway at approximately 65 miles per hour. If I don't use the 5-speed over drive to pass/change lanes, I'm at a half a tank by Thursday. I add between $3-$5 of plus gas when using the AC. My city has no car inspection or emission checks. Check the air hose connected to the air filter. If separation is visible in between the creases, moisture gets in the hose and it will cause the engine to not turn over. I went to a neighborhood junk yard and got another hose for under $6. My Aveo has 102K miles and still running strong!!Hope that helps!