What type of oil for a 1971 Porsche 911

l would use Royal Purple, personally. Mobile 1 is starting to get ''worse'' (not as good of an oil), so l would stick with royal purple. Weight depends on where you live.


just a note to mike T: a 71 911 doesnt have cats :)

Alot will depend on the state of the engine, & if it is appropriate to use synthetic. If the engine has been recently rebuilt, it should be a forgone conclusion that u would be better off using a synthetic oil: Redline would be my brand of choice here, though both Mobile 1 & Royal Purple r good options as well.

If the engine has been in service for a long time, u will likely have fewer problems staying with dino-oil (the smaller, more slippery molecules of synthetic will most likely expose new leaks with older seals). Kendall is a good brand (and go with a heavier weight, like 20-50). Though most major brands should be good choices, with the exception of Castol - a noted Porsche engine builder has consistently found sulfur buildup when doing rebuilds of engines that consistently used Castrol, & this seems to make a good argument to avoid this one major brand.

beware of the newest oils because they contain less of certain anti-wear additives, namely zinc. It is thought that these additives kill catalytic converters, debated heavily though. If your vintage car has a flat tappet cam it may wear prematurely with newer oils.
try Amsoil synthetic: http://amsoil.com/redirect.cgi?zo=1463115&page=products

l recently had a ''top job'' done to my '83 - 3.0, when l picked The car up the Mech informed me that he changed to Mobil 1, it was running conventional oil. The car has A/C and is a RoW model. After some extensive driving on open roads and our wonderful rush hour traffic in H-town I've noticed about a 10% drop in oil temp than before the switch. Ca not say about the long term but for an air cooled engine in 90+ degree ambient temps it seems to help.