August 17, 2018

Can I use HPS in my diesel engine?

Absolutely. All viscosities of HPS are formulated for use in gas and/or diesel engines and are ideal for those with modified diesels or those simply looking […]
August 17, 2018

Will HPS harm my catalytic converters?

No. Testing has shown no short or long term adverse affects on catalysts in mechanically sound vehicles.
August 17, 2018

What is the difference between HPS® and Royal Purple® API-licensed motor oils?

Royal Purple API-licensed motor oil is formulated specifically to meet current American Petroleum Institute (API), International Lubricant Standardization and Approval Committee (ILSAC), and Association des Constructeurs […]