The EU-version of the W205 FL comes with a OPF filter. Does anyone know if MB put this filter also in the US version?
This filter and the adjusted software in the ECU reduced the C63s from 510hp to 501hp.
Ím also under the impression that my 2021 C63s US version is louder then the same EU version. (Í m actually from Germany and remember the sound from a friends C63s FL)

Thanks

 

No, the US spec cars don't have the OPF. The EU spec sheets have it on there with its own option code, and it's not present on US spec sheets. The US spec cars have secondary cats just like before, while the EU spec cars have the secondary cats replaced with the OPF.

 

Thank you very much.
Then we just need to know if the ECU got modified in the FL to deliver “only” 501hp instead of 510 before the OPF in the EU.

 

First time I hear about the power being reduced. The FL is 1/10th faster to 60 than the PFL and its faster in the 1/4 mile. Also faster around the Nürburgring, beating the 204 C63 Black Series.

 

In the EU the PFL without the OPF has 510hp. The FL with OPF has 503, like my 2021 US model.

 

You are confusing units of measure. The C63S FL and PFL are rated at 510 metric horsepower in Europe, and 503 mechanical horsepower in the US. Not the same units of measure. 1 metric hp = 0.98632 mechanical hp

 

Now this makes perfect sense! That’s confusing. Wasn’t aware of the 2 different hp-ratings.
Thanks for your help. Much appreciated!

 

Yeah, to be specific, continental Europe generally uses metric hp, better known as PS or Pferdestärke for us German speaking fellows, but not always and US/UK uses mechanical horsepower or brake horsepower (bhp). The latter is slightly lower, because it takes mechanical losses into consideration and is more realistic, whereas PS is theoretical.

 

I don’t know who to believe honestly. While US spec sheet doesn’t include OPF as an option it still sounds toned down compared to preFL. My FL with catted downpipes sounds close to my neighbor’s stock prefl C63s and his car is still louder..

 

It's been confirmed by German tuners who sell their aftermarket exhausts in both markets. The US exhausts have secondary cats and the EU exhausts have OPFs. Generally lower volumes and the deliberate reduction of artificial pops&bangs is a different story and common to all markets. The OPF just further mutes the sound, because it's denser than a catalytic converter and fills up with the trapped particulates.

 

Also, one thing to be aware of is that for cars such as the W205, the OPF was an afterthought for the markets where it's required. The exhaust was never designed with an OPF in mind. New cars that are coming out that were designed with the OPF from the ground up aren't quite as muted. For example the new M3/4 despite OPF doesn't sound as muted in Europe. However, volume's in general are going down because of the regulations. For example the GT BS is very quiet, although I've only heard EU versions and just like our C63, the GT BS has OPFs in Europe and secondary cats in the US.