Why does the window sticker say 24 valve twin spark? This M273 5.5 liter 32 valve V8 has 8 spark plugs. I used to have a 2005 Chrysler 300C V8 that had two spark plugs so it is a thing, but why would the window sticker say 24 valve twin spark? See attached pic, lower left corner.

Where does the photo indicate 24V?

The M113 has 3 valves per cylinder. The S550 2007 did not use the M113.

That is very odd. The M113 was 5.0 and even the M113K was 5.4 so that's just....well, odd. No W221s got an M113, obviously. I guess it's just a typo. The 5.5 liter part is correct and the rest is wrong.

@Audiomikej do you own this car?

No, it is on BringATrailer.com. looks very similar to mine (same color and wheels) very rare it has no options and super low miles (19k)