Cadillac 2011 DTS Owner's Manual page 208

The speedometer shows the speed in both miles
per hour (mph) and kilometers per hour (km/h). See
MPH (km) under DIC Operation and Displays on
page 4 60 for more information.
The odometer mileage can be checked without the
vehicle running. The vehicle's odometer works together
with the driver information center. Trip A and Trip B can
be set on the odometer. See Trip Fuel under DIC
Operation and Displays on page 4 60 for more
information.
If the vehicle ever needs a new odometer installed, the
new one is set to the correct mileage total of the old
odometer.
4-46
This gauge indicates
the engine speed
in revolutions per
minute (rpm).