Does anyone know of an authoritative reference to the various W204 OEM springs? To keep it simple, I'm looking just for US-spec 250/300/350 sedans, not coupes or AMG models.

I would think Mercedes used at least four spring types on these sedans, based on:

1. 4 Cyl (250) vs. 6 Cyl (300/350)
2. Sport tuning ("Agility Control") vs. standard tuning ("Agility Comfort")

On the 6-cylinder cars there may also have been a difference between RWD and 4Matic due to the slightly higher weight of the 4Matic version.

 

I believed the only differences here for non AMG models was.

1) Sport tuning vs standard tuning
2) 4matic vs rwd.

I do not believe there was any difference on the C250 vs C300 as in your example. I have seen different P/Ns for #1/#2.