Q. You're telling me that modern cars automatically detect this problem, and therefore won't ping?
A. Right - as long as the load is not too great.
Load is the amount of work you're asking the engine to do, and it's affected by a number of factors, including climbing steep hills, pulling heavy weight, hard acceleration or driving in hot weather. Any combination of these factors can affect load. So, if you live out in the desert Southwest, it's 115 degrees out and you're hauling your mother-in law up, you're going to need premium.
Why? Because there's only so much that your car's knock sensor and computer can do to adjust the engine's timing.
“you're hauling your mother-in law up,”