>>My beetle TDI specifies full synthetic 5-40 to be changed every 5,000 =
>>miles--problem is I'm having difficulty finding 5-40.  Can I use 15-40 =
>>or some other grade of synthetic?  Can't get a straight answer from VW =
>>mechanics at my local dealer. =20

I have been running Castrol Syntec 5-50 in my rebuilt 1.9 wbx for the last 2 years with no problems.  Sorry no turbo experience.
George
'85 Westfalia