Our performance tuning for the 2005-2009 2.0l & 2.4l Chevy HHR typically yields 10-14hp and 1-2mpg (naturally aspirated, stock vehicles) or 20hp+ (forced induction), as well as better part throttle response, driveability, and more pep off the line. We can also account for any modifications you might have. Our tuning does not support the 2008+ 2.4L. After placing your order, please fill out an order sheet for your vehicle (here). What program should I use and what is refundable? Click here!