Originally Posted By: UG_Passat
Something to consider is the TBN's on 504/507 are typically nearly half as much as a 502.00/505.00/505.01 oil. If the 502.00 OCI is 10,000 miles (typical for VAG engines), obviously, don't expect the same OCI, maybe 5000 mile OCI is appropriate (verified by UOA's of course)
That's important to point out, but the relationship between OCI and TBN isn't exactly linear. Certain oils retain TBN better than others. Therefore, it's possible that a 504 could go 7-10k miles, but a UOA would be required like you said.