Cylinders that shut off at cruising speeds has been around for years. I thought Infinity has used that in their Q45 several years ago. Or maybe they were just testing it. It's supposed to be a nice way to save fuel but wasn't Chevy having problems with it in real use. I think there was a 5 second delay from when you punch the gas and when all 8 cylinders kick in again. Imagine that delay when passing someone on a winding highway. I think they came up with a computer fix for that now.