I've used ATF, new engine oil, Marvel Mystery oil, and now Stanadyne Performance Formula additive and they all work and lubricate. It's really up to how much you want to spend to get the job done.
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Chris Timochko
AUTO WURKS DIESEL R&D TEAM
1997 5sp 4X4, A. W. D. HX40 turbo, ATS 3pc Manifold, BD 4" Brake, Marine Compression, A. W. D. Custom Tuned Injection Pump, A. W. D. Intercooler, A. W. D. 370B Injection Nozzles, Delivery Valves, Governor & AFC Spring Kit, Psychotty Air, A. W. D. Water Injection, NOS Diesel Kit, A. W. D. 6" Chrome Exhaust System, BD No Smoke Valet Switch, McLeod Dual Disc Clutch, Mag-Hytec Rear Cover, Cummins Chrome Kit, Optima Red Tops, Hadley Bully Horns, Hurst Line Loc, Goodyear Wrangler AT/S 305/70/16s.