I've used both Redline and Power Service in my SD. I used Techron in a previous 1977 300D. Both the Redline DFC and the Power Service give a noticeable performance boost. Redline I've only found at Pep Boys; the Power Service is available at Wal-mart. Never tried the new Rotella DFC yet.

I tend to use a lot of either additive: I dump a half bottle of Redline in every other tankful or so, or a third of a 32 oz bottle of Power Service. I don't like to leave a partially-opened bottle in the trunk because of leakage and smells, hence the half bottle of DFC. I add it, then drive to the filling station.

__________________
Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic