15W-40 Rotella & a Navistar(most of the time) or Ford filter every 3000 miles. 10W-30 Rotella for 2-3 oil changes in Dec, Jan, Feb.. And a fuel filter every 50,000-60,000 miles, and an OEM pleated paper air filter when it's dirty, about every 50,000-60,000 miles also. I take oil analysis about every 9000-12,000 miles to make sure there's no problems. It's worked well for 277,000 miles & nine years so far.