Cadillac 2005 STS Owner's Manual page 205

AVG MPH (AVG km/h)
This display shows the average speed of the vehicle in
miles per hour (mph) or kilometers per hour (km/h).
This average is calculated based on the various vehicle
speeds recorded since the last reset of this display.
To reset AVG MPH, press the reset button. The display
will return to zero.
GAL FUEL USED (L FUEL USED)
This display shows the number of gallons or liters of
fuel used since the last reset of this display. To
reset GAL FUEL USED, press the reset button. The
display will return to zero.
MPG INST (L/100 km INST)
This display shows the current fuel economy. This
number reflects only the fuel economy that the vehicle
has right now and will change frequently as driving
conditions change. Unlike average fuel economy, this
display cannot be reset.
MPG AVG (L/100 km AVG)
This display shows the approximate average miles per
gallon (mpg) or kilometers per Liter (km/L). This
number is calculated based on the number of mpg
(km/L) recorded since the last time this display
was reset. To reset MPG AVG, press the reset button.
The display will return to zero.
MILES RANGE (km RANGE)
This display shows the approximate number of
remaining miles or kilometers you can drive without
refilling your fuel tank. This estimate is based on
the current driving conditions and will change if the
driving conditions change. For example, if you are
driving in traffic making frequent stops, the display may
read one number, but if you enter the freeway, the
number may change even though you still have
the same amount of fuel in the fuel tank. This is because
different driving conditions produce different fuel
economies. Generally, freeway driving produces better
fuel economy than city driving.
Once the range drops below 40 miles (64 km) remaining,
the display will show LOW RANGE.
If your vehicle is low on fuel, the Fuel Level Low
message will be displayed. See "Fuel Level Low"
under DIC Warnings and Messages on page 3-74 for
more information.
MPH (km)
This display, if equipped, shows the vehicle's speed
digitally in either miles per hour (mph) or kilometers
per hour (km/h).
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