Since the introduction of synthetic lubricants, automotive maintenance has changed drastically. Some automotive manufactures’ recommendations have reached oil change intervals in the 15k and even 20k mile realm, but this does not mean that it is the best recommendation for your engine’s health and extended life.
The modern Porsche’s (e.g. the 986-987s and 996-997s) require a more vigorous engine oil change schedule. We suggest that you change your engine oil and filter every 3-5k miles or 6 months (whichever comes first) based on how your car is driven to insure clean internal engine component operation. For cars driven primarily shorter distances (under 10 miles) and/or stop and go traffic a few times (or less) per week, a shorter oil change interval is needed. Cars driven longer distances regularly will do fine with a slightly longer oil change interval.
While these service intervals may seem conservative, it is important to recognize that modern synthetic engine lubricants rarely wear out in these shorter intervals, but mainly become contaminated with combustion byproducts and water condensation (worst in periodic short distance driving). In the case of extended intervals, viscosity and anti wear additives wear out sooner than the engine oil’s base stock. Changing the oil more frequently will help to protect against the potential problem areas such as failure of the Intermediate Shaft Bearing, Cylinder Liners and Chain Tensioners.
A good practice, when changing your oil and filter, is to cut your filter open to inspect it for any metal and plastic debris. This debris can be the early signs of an internal engine problem. There are also quite a few ancillary items that require clean engine oil to operate properly, such as the Vario-Cam and Vario-Cam Plus control solenoids, chain adjusters, camshaft vane cell adjusters and hydraulic valve lifters, just to name a few. These components all have very small oil passages and galleries which can get clogged with even the smallest particles of dirt and debris.
The Environmental Protection Agency (EPA) has mandated engine oil manufactures to reduce the high pressure/anti wear additive named Zinc dialkyldithiophosphates (ZDDP). The whole reason for this mandate is to help prolong Catalytic Convertor life and efficiency. Modern Porsche engines, which are of flat tappet design, require a substantial amount of ZDDP additive in the engine oil to protect and lubricate all the valve train components.
Today we see many engines with camshaft pitting and lobe erosion at a relatively low mileage, these issues are a direct result of utilizing oils with reduced levels of ZDDP. We highly recommend that you stick with one of the higher quality but smaller “Boutique type” engine oil manufactures such as Redline, Motul, Swepco and Brad Penn that have ZDDP levels above 1,250 PPM to combat these issues. These oils are a little more expensive and can be difficult to obtain, but they will save you significantly overtime in repairs you will not have to perform.
Tony Callas & Tom Prine