I tried 5.5 quarts of this oil in my 1998 Audi A4 with 2.8 V6, 30-valve engine with 160,000 miles. With this Ultra oil I often (maybe 1/2 the time) get valve chatter for about 1-2 seconds on cold or warm startups, even now in a garage where it's 70F overnight.
The chattering is common in these...