TNSIG,

I use regular ole dino oil recommended weight and change no earlier than recommended interval.

The last car I had oil checked in was my Diesel Rabbit because the oil was always immediately BLACK and it bothered me. VW recommended something like 7500 mile interval and the dealer of course suggested 1000 mile.

This oil change interval uncertainty always kept me up at night so I had it tested. When at 7500 miles on the rabbit the report came back that the oil was still fit and capable of another 4-6k miles easily.

Soooo like you said, you shouldnt go wrong with following the suggested engine oil change interval in the manual. The transmission fuid interval may be different as Bob Wilson has noted based on the oil tests, not simply a matter of opinion.

Sorry for the long winded reply.

Tony