In the last week I have changed the oil in both of my cars. One is a 1963 356 and the other a 2022 Boxster S. Both of these cars have horizontally opposed 4 cylinder engines but they are totally different in almost every other aspect. So the engines in our cars have evolved since 1963 and into engineering marvels. The Boxster boasts 350Hp from an EFI, Turbocharged, quad valve, variable cam masterpiece of engineering. Meanwhile the 356 is an air cooled, 80Hp, flat tappet, Zenith carburetor equipped engine that, for it’s time; proved to be a great race platform and an undeniably reliable piece of machinery.
The evolution of automotive engines is pushed by many factors. Environmental, Reliability, Economics and better engineering of not only the engines but every component of the engine. With computers now monitoring every aspect of the engine. I think we would all agree that the changes have been for the better even though there have certainly been growing pains.
So back to oil. As my cars are totally different it stands to reason that the oil requirements would also be different. Porsche recommends their Classic 20W 50 for all cars thru the 1977 2.7l. This oil is a proprietary mixture that was developed in Weissach. I have not tried this oil, there are many other oils that will work in the 356 and the opinions on which is the best vary greatly. So far I have run 2 oils in my engine. First a “Break in Oil” from Lucas Oil Products, it is a very high “zinc” oil that is important for protecting the cam and flat tappets in the engine. I used a 20W 50 in this oil and it worked well. When I changed the oil this week it had 440 miles on it and had the very small amounts of “metal” and bearing particles in it. I feel the engine is broken in and it didn’t burn any oil during this initial break in. The oil I used to fill the engine this week is PennGrade partial Synthetic also in 20W50. I feel this will be a good transition oil to full Synthetic at my next oil change. The engine is still breaking in so I’ll change it again after the East Coast Holiday in North Carolina at the end of next month. I am currently leaning to Valvoline VR1 full synthetic in 20W 50 for the normal use at the next oil change. This is a high Zinc oil that is needed to protect the valve train and a higher viscosity for the larger tolerances in the old engine.
The recommendation for the 2023 Boxster is Mobil 1 ESP in 0W 40 weight. Weissach has worked with Mobil for the last several generations of Porsche vehicles. This carries the Porsche C40 Approval rating. This was the 3rd oil change on the Boxster as I am OCD about the turbocharger and keeping the oil clean for. I am changing the oil every 5,000 miles, the Porsche recommended interval is every 10,000 miles. So far I have not found another oil with the C40 approval and I probably wouldn’t change any way. The ESP designation is for Emission System Protection and is used to protect the catalytic converters. I have had to order the oil on Amazon but found it at one AutoZone in Lexington.
Conventional vs. Synthetic is a discussion that is heard, especially with the more vintage cars. While there may be some benefits to conventional on very old vintage automobiles, I believe that the benefits of Synthetics out weigh the negatives. The negative for Synthetic in vintage cars is that some of the seals and gaskets are not compatible with some of the chemical make up of the oil. Most, if not all seals and gaskets for vintage cars are now made of modern materials so this, in my opinion is a moot point. Synthetics are engineered to better protect engines, keep them cleaner and prolong the life of the oil. Thus reducing the oil change frequency, some up to 20,000 miles. These engineered oils are the only thing to use in modern engines. With tight build tolerance and turbos on most all new Porsche vehicles, the demands on the oil are far more than a conventional oil can handle.
If you want to keep your Porsche all Porsche here are the Porsche oils for the classics:
Description Models Part #
Porsche Classic 20W-50 356 (1948-1965) 00004320928
911 F Model (1965-1973)
911 G Model (1974-1977)
only for 911 up to 2.7 liter
Porsche Classic 10W-60 911 G Model (1978-1989) 00004320930
only for 911 from 3.0 liter
Porsche Classic 10W-50 924 (1976-1988) PCG04321010
Porsche Classic 5W-50 986 (1997-2004) PCG04321050
All of the newer Porsche vehicles have been factory filled with Mobil1 of the correct weight. Check your owners manual for the correct viscosity. There are many brands that will meet or exceed the Porsche A40 and C40 ratings, Mobil1, Motul, Liquid Moly, Castrol etc. Use what is best for your application 0W-40, 5W-40 or if you track the car maybe something else, just make sure it meets the Porsche Approval Ratings.
Oil changes are pretty easy to DYI so there is no reason not to keep this very important maintenance item up to date.