You should check your car's oil every 1 to 2 weeks, when refuelling, before a long journey, or as recommended by your owner's handbook
Oil should be clear and semi-viscous in appearance. Dark or thick oil has covered a high mileage and will be losing its effectiveness to protect your car's engine.
A low oil level, or low oil pressure, can seriously damage the engine or cause it to overheat.
All engines consume oil as part of their normal operation, but a low oil level can indicate that there is a leak.
A new oil filter should also be fitted as a matter of course whenever the engine oil is changed.