My 2010 Cummins requires a full synthetic oil. So I use Valvoline 5W-40 full synthetic changed every 3,000 miles. I do a lot of in town driving and feel the relatively short change interval is best (I bought the truck new and it just turned over 51,000 miles). As for filters, I use NAPA Gold filters for fuel, air, and oil.

"We live in a time when intelligent people are being silenced so that stupid people won't be offended".