Wanted to post this in the last bread.
Here is red pill for you…
Cummins still makes a turbodiesel inline six for trucks, the Cummins B Series engine, originally displacing 5.9 liters but now increased in capacity to 6.7 liters.
The last gasoline inline-six I’m aware of that was manufactured by an American company is the General Motors Atlas LL8, displacing 4.2 liters and used in SUVs like the Chevy Trailblazer. Production ended in 2009.