The biggest threat to six cylinder engines is the turbo-4 and turbo-3. A lot of these turbo 4 cars nowadays are not all that efficient in real world driving, but a turbo-4 is very good at gaming the EPA tests, which decide the numbers that go on the sticker.
Most of these engines are running enough boost, that if a hose clamp slipped off, your hood would probably sheer the hood latch off :)
Boost has to have equal amounts of fuel. Some of these 4’s are breathing better than big block V8 engines when they are at full boost.
Add to that, that a 4 banger is very inexpensive to manufacture in mass quantities, and I think the 6 cylinder’s days are numbered as well.
I welcome our electric overlords, once they have the battery tech sorted out (or Mr. Fusion is available). There would be no better way to tow a trailer than a electric pickup with so much grunt at the very start of the pedal range, and delivered so smoothly. I envy the CSX locomotives that pass my backyard daily :)
And the RPM potential!
“Some of these 4’s are breathing better than big block V8 engines when they are at full boost.”
A few years ago (may still be true)the most powerful crate engine you could buy was a twin turbo 4cyl that developed 1050 hp. (I can’t imagine the sound.)