San Diego Gas and Car Wash

How come I still need to change my oil at 3000 miles even though I use synthetic?

In determining oil change intervals using SYNTEC, Castrol leans toward the conservative side and recommends following the engine manufacturers’ guidelines found in your vehicle’s manual for the specific type of driving you do.

This is important because combustion byproducts and other contaminants are still going to build up in any type or brand of engine oil. A number of factors including the engine design, type of driving, weather conditions, oil filter used, etc. determine how much buildup is created. By changing your oil frequently, you remove by-products of combustion such as acid, soot, abrasives, water and unburned fuel. All of these substances can have damaging effects on both the performance and life of your engine.

Manufacturers recommended service intervals today cite maintenance schedules based on ‘Normal Driving Conditions’. If you short trip the vehicle, drive in traffic, travel at speeds over 60 mph then you are in all likelihood running a ‘Severe Driving Condition’ interval. If you read the fine print on many of the oil life monitors and how they work they point out that in the event of battery disconnect or power loss revert to a 3 month/3,000 mile oil change interval. Why? Because it establishes a base point and it is the safest interval for maximum engine protection and longevity.

We have tested our oil under considerably higher oil change intervals and it has performed very well however with the number of unknowns as mentioned above, we must err on the side of caution and reiterate that the manufacturers’ recommendation be followed.

We recommend for ultimate protection that you change your engine oil every 3,000 miles or 3 months (whichever comes first).

Posted in: Castrol