Engine oil Castrol or AMSOIL

castrol 5w40 is what vw puts in the new passat. just did my 5k oil change the other day. i used a original vw oil filter also.

I use Amsoil full synthetic 15w-40 year round in my 1.6D with over 250k miles.

All oil changes on this car have been done with Castrol Syntec 10W30 Full Synthetic and an OEM Mazda Filter.

Amsoil 20w50 in my 8-v 12:1+ 1.8 liter Rabbit Amsoil 5w-40 in my street turbo Jetta and track turbo Golf.

From what I can find, Castrol makes a 0W30 longlife oil which can be used in VW engines which have sensors which support the longlife service regime. According to this regime, oil change intervals can range from 9,000 miles or 12 months to as long as 30,000 miles or 24 months - IF the sensors will allow such an extended interval.

In the early years only VW dealers carry Castrol Syntec 5w-40 oil which is where I am always getting from.

I switched to amsoil 20w50 and the temps are down to 230ish

With the AMS and a 20 row cooler my temps stick at 190-200 dependant on ambient temps thus far.

Stick with the synthetic. The tiny turbos on the TDI's are heavily stressed and mineral oils are just not up to the task of protecting the bearings in the turbo.

amsoil here too, right now 5w30 going to switch to 0w30 soon, best stuff for the $$$