and camshaft design (increased exhaust valve duration). The engine also switched from wasted spark ignition to individual coil-on-plug ignition. Upgraded engine was controlled by new 32-bit ECM (E37). These changes increase horsepower slightly and retain similar fuel economy. Ebony interior now available. 2008: New "SS" model introduced. "Half Panel" RPO code AA5, rear quarter window delete, option added. Tire pressure monitoring system now standard (except in Canada). GM's OnStar was also now included with every model. Electronic stability control is available as an option. Four new exterior colors available. 2009: Flex-Fuel (E85) was added to the 2.2 and 2.4 engines. The 2.2 engine now comes with Variable Valve Timing (VVT).The interior was slightly changed: power window control switches were relocated from the lower center dashboard to the more traditional driver-side door; interior overhead lighting was improved; AM/FM stereo with USB port was now optionally available on LT/SS models. Side curtain airbags & electronic stability control is now standard across all models (except in Canada). 2010: GM phased out all GM badges from the front doors halfway through the model year (2010.5). 3 new paint colors added (8 total), down from 10 color options in 2009. Side curtain airbags & electronic stability control is now standard for Canadian models. Last year for "Half Panel" RPO code AA5, rear quarter window delete option. 2011: SS model discontinued. Cashmere interior removed from options. Engines Flex-Fuel (E85) was added to the 2.2 & 2.4 engines for the 2009 model year; these were the first Four-Cylinder Flex-Fuel Engines from GM in North America. Safety In Insurance Institute for Highway Safety (IIHS) tests the HHR received a "Good" overall score in the frontal offset crash test, and an "Acceptable" score in side impacts on models equipped with side curtain airbags. Side curtain airbags became standard for 2008 models. However, side torso airbags were never made available. Sales See also Chevrolet SSR Chevrolet Advance Design, the 1947-55 Chevrolet pickup References External links Technical Information Chevrolet HHR HHR Crossover sport utility vehicles Vans Front-wheel-drive vehicles Retro-style automobiles Cars introduced in 2005 2010s cars Panel trucks