Delvac 1 is some really, really good stuff. With proper filtration, they claim 100,000 mi drain intervals (for big rigs that is). Basically, it's Mobil's best synthetic plus additional detergents, foam inhibitors, and zinc for exceptional high temp wear characteristics. We couldn't find technical specs anywhere and I somehow got my hands on the Exxon/Mobil engineering support hotline and we got to speak directly to the people who designed the oil (not those marketing it) and we were able to clear up lots of confusion on the subject on compatibility with gas engines as well as sufficient evidence to back their fully synthetic claims.
We use it in our tricked out aircooled motors with great success. My next oil change I am going to put Delvac 1 in my 1.8T to see how it compares with Royal Purple's Racing 41 7w40 I am currently running.
OT, but who does oil analysis and how can I purchase a test kit?
LN Engineering http://www.LNengineering.com
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