Your HHR SS reqiures GM 4718M oil! That doesn't necessarily mean Mobil 1
However that is what the car comes with from the Factory.........
I assume you have an Owners Manual that came with the car????

 

I run Mobil 1 in my LT1 with its 2.4L. I've run Mobil1 in my 88 Fiero when the engine was replaced with a 3.4L, now it has AMSOIL synthetic.. I did run Mobil 1 in my 99 Buick Regal GS to over 100K miles. I haven't had any engine problems with my cars running Mobil 1. Good stuff

 

My mistake it has Mobil 1, I was too short to see the top of the oil cap, says Mobil 1...but hey thanks for all the help folks !