There seems to be a growing school of thought from dealerships promoting the idea longer synthetic oil life. People are being told that changing your oil every 15-25 thousand km’s is a good idea if you use special synthetic oil. The fact of the matter is…..leaving your oil change intervals this long is EXTREMELY bad for your engine.
Oil has a finite lifespan and serves 5 major functions. It cleans the moving parts while lubricating them. It also fulfills a cooling function, absorbs the impact of various parts and helps in sealing the engine to prevent leaks. Customers have reported (who have decidedly increased the length of their change interval) that after 8 thousand kilometres they need to add oil to maintain the appropriate fluid level. This type of activity can eventually lead to a variety of engine issues over time. Once the oil has met its expiration date, it no longer serves the 5 major functions it was designed for and consequently begins to burn off and diminish most often leaving deposits behind in the process.
It simply does not make sense that a manufacture should recommend two different oil change intervals for the same engine (using the same synthetic oil) simply because of the car brand. Why do they do it? Many of the German car manufactures are now offering extended warranties that include free oil changes for the first 80,000 kilometres (as an example). It stands to reason that the car manufactures are saving more money by doing less frequent oil changes, but at YOUR EXPENSE! When your warranty is expired, it is you that has a car in potentially poor mechanical condition and they (the manufacture) are no longer liable. The choice is yours to make. However keep in mind that oil changes are less expensive than serious mechanical repairs.
Just ask yourself:
Would you ever use the same laundry soap to do 3 loads of laundry? And does special soap only require you to shower every 4 days instead?