Ericv13

What can I do to make my C250 a bit more “potent” ? It is stock with the exception of a K&N air filter (oem style) and muffler delete .

michail71

If you're talking about HP, not much realistically.

Upgraded brakes, sway bars and using something like Michelin pilot super sport tires would help with something like track times.

You can get an add on box that tricks the ECU's sensor inputs for a little extra power. But would likely cause CELs and limp mode.

Without the availability of any ECU flashes for this platform bolt-ons would be pointless.

edgalang

The biggest performance upgrade you can do on any car is to upgrade the tires.

Michelin Pilot Super Sports is a good start.

dol4er

You could go for a plug-and-play tune box from Brabus. Other than a tune box, there is nothing you can do that will lead to performance improvement.