Opening/closing automatically from outside
See also:
Snow chains
For safety reasons, Mercedes-Benz
recommends that you only use snow chains
which have been specially approved for your
vehicle by Mercedes-Benz, or are of a
corresponding standard of quality.
...
Checking tire pressure manually
To determine and set the correct tire
pressure, proceed as follows:
Remove the valve cap of the tire that is to
be checked.
Press the tire pressure gauge securely onto
the valve. ...
Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of
tires with regards to tread quality, tire traction
and temperature characteristics. Ratings are
determined by tire manufacturers using U.S. government ...