Ask a Question

Technical Questions

Can't find an answer in our Help Center? Submit a question, and we'll get back to you soon.

Need Business/Order Related Support?

Search our Help Center
Get answers to business and order questions from our experienced Customer Service representatives.

Website Feedback

How are we doing? We really are interested in knowing how you feel about DX Engineering. Contact us with your comments - good, bad, great, so-so, or whatever. We want to hear from you!

Royal Purple HMX® High-Mileage Synthetic Motor Oil: A Must-Have for 75,000 Mile-Plus Engines

Metal engine components can take a hit as the miles increase with engine seal deterioration, brittle gaskets, ring wear, or valves that stop sealing correctly—but Royal Purple HMX High-Mileage Synthetic Motor Oil can help. Engineered specifically for gasoline engines with more than 75,000 miles, Synerlec® technology additives bond with metal components to provide superior protection against corrosion, wear, and thermal breakdown—even during cold-starts. Plus, the synthetic formula is packed with zinc and phosphorus, and is chemically enhanced to work as a conditioner, softening hardened or brittle seals to restore the pliability needed to seal tightly for fewer leaks, better oil breakdown, and less oil consumed.

Additional features include:
• Exceptional oxidation stability
• Tough detergents to remove deposits and extend engine life
• Safely extends oil drain intervals up to 15,000 miles or 12 months for unmodified,
mechanically-sound engines with proper filtration
• Meets or exceeds API SJ, SL, SM, and SN specifications
• Available in 5W20, 5W30, or 10W30 weights

SEE ROYAL PURPLE HMX HIGH-MILEAGE SYNTHETIC MOTOR OIL AT SUMMIT RACING