How many miles can I go between oil changes in vehicles that use diesel engine oil?

Royal Purple suggests adhering to manufacturer’s recommended oil change intervals for vehicles under warranty. Vehicles no longer under warranty using Royal Purple Duralec Super, Duralec Ultra, or HPS engine oils, that hold 10-quarts of oil or more, can extend oil change intervals up to 15,000 miles (24,140 km) or one year, whichever occurs first in street-driven, mechanically-sound vehicles. For smaller capacity engines, oil change intervals should be every 12,000 miles (19,312 km) or one year. For guidelines specific to your vehicle, we recommend contacting our technical department at rpautotech@royalpurple.com