Do hhr have to have premium gas?

The Chevrolet HHR is designed to run on regular unleaded gasoline with an octane rating of 87. While using premium gasoline (91 octane or higher) is not required, it may provide slight performance improvements in terms of engine power and efficiency for some models, particularly those with turbocharged engines. However, for most HHR models, using premium gas is not necessary and will not significantly impact overall performance. Always refer to the owner's manual for specific fuel recommendations.