Dads 1993 Chevy Silverado 1500 with 121,353 mile 350. Drained out Castrol HIGH Mileage 10w-30 and spun off STP ST5 oil filter. Poured in 5 quarts Valvoline NEX-GEN 10w-30 and spun on a New NAPA Pro-Select oil filter.
in: Warren-Coastal (Farm and Fleet label) 5w-30 Black Bosch filter
note- with Castrol, engine burned a quart every 4000 miles. With Warren its every 1000 miles. I will switch to either M1 high mileage or Valvoline HM full synthetic next time