Mercedes-Benz C-Class (W205) 2015 - 2021 Owners Manual: Information on using a power washer

WARNING Risk of accident when using high-pressure cleaning equipment with round-spray nozzles

The water jet from a round-spray nozzle (dirt grinder) may cause damage to tires and suspension components that is not visible.

Components damaged in this way may fail unexpectedly.

Do not use high-pressure cleaning equipment with round-spray nozzles to clean your vehicle.
Damaged tires or suspension components must be replaced immediately.

To avoid damage to your vehicle, observe the following when using a power washer:

keep the SmartKey at least 10 ft (3 m) away from the vehicle. Otherwise the trunk lid could open unintentionally.
maintain a distance of at least 11.8 in (30 cm) to the vehicle.
vehicles with decorative foil: parts of your vehicle are covered with a decorative foil.
Maintain a distance of at least 27.6 in (70 cm) between the foil-covered parts of the vehicle and the nozzle of the power washer.

Move the power washer nozzle around whilst cleaning. The water temperature of the power washer must not exceed 140 ºF (60 ºC).
observe the information on the correct distance in the equipment manufacturer's operating instructions.
do not point the nozzle of the power washer directly at sensitive parts such as tires, slits, electrical components, batteries, light bulbs and ventilation slots.

Washing the vehicle by hand

Observe the legal requirements, e.g. in a number of countries, washing by hand is only permitted in specially designated wash bays.

Use a mild cleaning agent, e.g. car shampoo.
Wash the vehicle with lukewarm water using a soft car sponge. When doing so, do not expose the vehicle to direct sunlight.
Carefully hose the vehicle off with water and dry using a chamois. Take care not to point the water jet directly towards the air inlet grille.

Mercedes Benz C-Class (W204) 2007 - 2014 Training Manual > Body and Safety: Improvement in corrosion protection compared to model series W 203
Body Fully galvanized body (even as of model refinement package 203) New door frame system with dry area and continuous peripheral seal Door bottom edges folded-over with seam seal and wax in the cavities Handle strip on trunk lid with centering and chafe protection Door handle recess on trunk lid w ...