Visit mitsubishicars.com, select Owners, create an account and enter your vehicle information. Once you are registered, you are able to download various info such as your owner's manual and warranty & maintenance manual which explains your maintenance schedule. Not knowing how many miles are on your Mirage, you probably just need a simple oil change, or maybe the maintenance schedule calls for more.
I'm going to guess you didn't buy your Mirage through a Mitsubishi dealer, as I would expect they (or any reputable dealer) would perform maintenance service before selling it. If you bought it through a dealer, you might want to consider giving them a call and asking them about this.
Good luck and let us know how this turns out for you.
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View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)