Copper Clad Wire

You get what you pay for. Aluminum wire was a less expensive material for building mobile homes. The entrance cable to your home meter can is likely aluminum too.
It's not going to move in that application but it will pay to tighten those lugs once every 5 years.
I use aircraft grade wire in building IVRs. Sure it drives the cost up. Failures and worry about failures goes waaaaay down.