Motor Oil

Is HMX® different from your API-licensed engine oils?

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.

Can your oil be used with flat tappet cams?

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.

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