Not so true anymore.... our 2013 Impala is 11.5:1 and recommended fuel is 87 octane.
Yes, that's why I said, In 99% of engines made, the compression ratio determines the octane of fuel required.
I have seen Chevrolet say, premium fuel is recommended, but not required, in SS impala's.
There are some things engineers are doing to get around the detonation issue.
I read about a new engine being developed, which will now have variable compression. I'm not going to be volunteering my money, to do testing on that for them. But, I suspect they will get there.