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From 2006 Astra owners manual .
In order to guarantee economical and
safe vehicle operation and to maintain
the value of your vehicle, it is of vital
importance that all maintenance work
is carried out at the proper intervals as
specified by Vauxhall.
In vehicles with a fixed oil change and
service interval, InSP appears in the
odometer display when the ignition is
switched on if the vehicle is due for service.
Have service work performed within a
week or 300 miles (500 km). We
recommend that you contact your
Vauxhall Authorised Repairer.