What gear oil is best for my Porsche transaxle (manual gearbox)?
There are many excellent choices for gear lubes, both synthetic and non-synthetic that are appropriate for use in our transaxles. I have had excellent success with the tried and true Swepco 201 80W-90 gear oil everyone has been using for years, but many do seek the benefits of a synthetic hypoid or gear lube. For transaxles that call for a GL-4 spec gear oil, I have had excellent results with Amsoil’s fully synthetic GL-4 gear lube, not to be mistaken with a GL-5, which is “backwards compatible.” Another excellent GL-4 is manufactured by Redline, MT-90, which is a true GL-4 75w90 gear oil. For transaxles that are compatible with GL-5 spec gear lube, you have many choices. Swepco for starters, being the most popular choice for gear lube among most Porsche owners. Royal Purple makes an excellent Max Gear lubricant, which I have found to work well in worn transmissions that need extra cushion or have notchy shifting. I have also run Redline’s 75w90NS in a 901-transaxle- this formulation d
