Yes, HMX is fortified with Royal Purple’s proprietary Synerlec additive technology as well as additional seal conditioners beneficial to higher mileage engines to maintain elasticity of gaskets and seals. HMX is also formulated with a slightly higher amount of anti-wear additive to provide more wear protection for older engines.
While no special oil filter is required, we do recommend upgrading to a high quality oil filter. A high quality filter will prevent contaminants from circulating through the system and causing damage. For best performance and filtration, we recommend Royal Purple Extended Life Oil Filters. See our oil filter information page for more details or …
Is a special oil filter required when using Royal Purple? Read More »
Yes. For stock, non-performance valve trains, Royal Purple API-licensed oils (API SN and ILSAC GF-5 licensed) are OK. For upgraded performance flat tappet camshafts, and vintage high performance engines, we recommend our HPS or XPR engine oils. For a specific recommendation, contact our tech department at 888-382-6300.
Yes. All Royal Purple® engine oils contain the zinc/phosphorus compound zinc dialkyl dithiophosphate (ZDDP), but the maximum amounts are restricted by the current API oil specifications. For stock, non-performance automotive street applications, API SN licensed oils are OK. For better wear protection, Royal Purple HPS and XPR lines of engine oils are formulated with a …
