3. CARS


Learn the essentials about putting the right motor oil in your car, whether synthetic or otherwise.

How Do I Know What Oil to Put in My Car?

How Do I Know What Oil to Put in My Car?

Choosing the right motor oil for your car is very important to ensure proper engine protection and to cover any conditions that may be required to maintain your vehicle’s warranty.   Motor oils can be very different and are formulated to meet certain performance specifications and SAE viscosity grade requirements.   Motor oil performance requirements will be dependent upon the oil specifications by vehicle and this will be determined by the manufacturer.  


Which oil you choose for your car will be dependent upon the vehicle, the model year and the engine type. Determining factors include is the engine gasoline or diesel, engine size or displacement, use of turbochargers or direct fuel injection, and incorporation of emission control components such as catalysts and particulate filters. 


For additional help determining which oil to use, try Castrol’s Oil Selector tool.  


What Motor Oil Should I Use In My Car?  

The best source of information is your vehicle owner’s manual.  The manual will provide the necessary details on the proper oil viscosity grade (e.g. SAE 0W-20, SAE 5W-20, SAE 5W-30 or other) as well as the performance specification.  Specifications will generally refer to ILSAC performance categories (such as GF-5 or GF-6) and/or API performance categories (Such as API SN, SN PLUS, SP).  In these cases, there may also be pictures or symbols, developed by API , that you will find on motor oil labels.  These can be used with the viscosity grades requirement, to confirm the proper choice.  See examples below

What Motor Oil Should I Use In My Car?

Where OEMs have specific motor oil performance recommendations certain approvals may be necessary and these will be identified in owner manuals.  Examples include GM dexos specifications which include a licensed logo found on motor oil labels (see below) as well as motor oil for European vehicles.  European manufacturers specify the proper motor oil through their own specifications which in most cases involve motor oil brand approvals. Examples include Mercedes Benz 229.5, VW 502 00 and 505 00 and BMW Long-Life 01.

 In addition to the right oil, one should always change the oil at the frequency recommended in the owner’s manual or as identified by the oil life indicator on the car’s dashboard.


How Much Oil Should I Put In My Car?  

The amount of oil required will be identified in owner’s manuals.  A second check will be the marks that are on the oil dipstick.  After validating the amount of oil required the dipstick can be used to confirm that the proper amount of oil had been added. It is important to not underfill or overfill the crankcase to ensure proper protection.


Does my car require synthetic oil?

In general, manufacturers recommend motor oil based on viscosity grade and performance specification.  In cases for GM where dexos is required, European manufacturers specifications and where SAE 0W-20 is recommended, such oils will be formulated with synthetic technology.  In all cases a synthetic oil can be used even if a conventional oil is suitable to gain further performance benefits afforded through synthetic technology.