Toyota Lexusc Owner's Handbook Manual page 122

(2) Average vehicle speed after engine start
("AVG MPH" or "AVG km/h")
Average vehicle speed after engine start is calculated and
displayed based on total driving distance and total driving
time with the engine running.
The displayed value is updated every 10 seconds.
To reset the calculations, push and hold the "INFO" button for
about 1 second when the display indicates the average vehicle
speed after engine start.
(3) Average fuel consumption after refueling
("AVG MPG" or "AVG L/100 km")
Average fuel consumption after refueling is calculated
and displayed based on total driving distance and total
fuel consumption with the engine running.
The displayed value is updated every 10 seconds.
The calculation is reset when the vehicle starts after refueling.
GAUGES, METERS AND SERVICE REMINDER INDICATORS
(4) Instantaneous fuel consumption
("MPG" or "L/100 km")
The instantaneous fuel consumption is calculated and
displayed based on distance and fuel consumption for 2
seconds with the engine running.
The displayed value is updated every 2 seconds.
Note that an accurate figure may not be shown in the following
cases.
D When the vehicle is stopped with the engine running, the
display will indicate the extremely high fuel consumption.
D When the vehicle is driving down a long slope, applying the
engine brake, the display will indicate the extremely low fuel
consumption.
(5) Driving distance after engine start
("Distance miles" or "Distance km")
The driving distance after engine start is calculated and
displayed based on vehicle speed after engine running.
The displayed value is updated every time the fuel equivalent
for 0.1 km or 0.1 mile is consumed.
To reset the calculations, push and hold the "INFO" button for
about 1 second when the display indicates the driving distance
after engine start.
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