More power consumption on its own should be enough to make it not ok.

There’s also heat, noise, and drive lifespan.

Do people order 6 cylinder mustangs because that’s what they want or because they can’t afford the 8?

Mustang owners might be an exception but I would be upset if I was hypothetically sold a V8 Toyota Camry when expecting a four-cylinder, even if I only paid the lower price.

I have a very standard commute where I drive boring and defensively. I enjoy cars as much as they get me from point A to B. There would be no benefit for me spending extra money despite the "better" engine.

If I bought a Prius and they gave me a V8 I sure as heck would.

That's an interesting take on my analogy.

I don't know if they advertised it as a low power drive, but if they did it would be surprising in a negative sense.

That is exactly why you’d want 5400 RPM in a non-budget drive; lower power, lower noise, longer drive lifespan.

> I wonder if mustang guys ordered a 6-cylinder mustang and got the v8 - would they complain about gas mileage?

Why wouldn't they? They were fraudulently sold a vehicle that didn't meet the claimed specs.