Royal Purple Duralec Ultra Diesel Motor Oil

4.69 out of 5 stars 16 Customer Reviews

Royal Purple Duralec Ultra diesel motor oil is specifically formulated to maximize performance and meet the demands of today's heavy-duty engines. Duralec Ultra is

Royal Purple Duralec Ultra diesel motor oil is specifically formulated to maximize performance and meet the demands of today's heavy-duty engines. Duralec Ultra is fortified with a high level of zinc/phosphorus anti-wear additive, along with Royal Purple's proprietary Synerlec additive technology. Synerlec creates a tenacious ionic bond with metal surfaces, providing protection upon startup, and greatly increased film strength that helps to eliminate metal-to-metal contact, even under severe conditions.

Additional performance advantages include:

* Superior corrosion protection
* Low coefficient of friction results in optimized fuel efficiency
* Better wear protection
* Natural solvency keeps engines cleaner than detergents alone
* Oxidation and heat stability greatly extends oil drain intervals
* Compatible with other mineral and synthetic motor oils
* Reduces exhaust emissions
* Mates engine parts
* Will not harm seals
* API warranty compliant
* Recommended for 2- and 4-cycle diesels; including automotive, commercial fleet, and stationary industrial applications