MPG Problem HELP
i just bought a 2009 chevy cobalt sdn, auto with 45K miles from the dealer. i noticed i get about 200 miles to a full tank, at least half of that was highway miles. I dont know why this is, oil just changed and air filter changed, wheels are aligned. I read on a forum where this guy said he had the same problem with his, so he took his car somewhere and got a "trifecta" tune that took him from 200 a tank to 360 a tank. is that what i need to do, if so, where would i go for that and if i did tune it to get better mpg, would it void extended warranty i got with the car? i got a 60 month/60,000 mile warranty with it. any advice would be greatly appreciated! Thanks for looking.
Also, what is recommended tire pressure for this car? and im reading forums with people getting like 40 to 50 mpg with their 09 cobalts!, something wrong with mine, should i take it in???
Last edited by Deven534; 02-06-2014 at 09:29 PM.