5w30 is recommended
what weight oil used for 2004 Chevy silverado the standered is usually 5 w 30
80 or 85W 90 gear oil.
Factory says to use 5W30 and A/C Delco oil filter.
5W30 weight only. Your choice of brands.
10w-30
Factory said to use 5W30 weight.
SAE 5w20 any major brand.
5W30 weight in the winter months and 10W30 in the hot months.
80W90 / 85W90 it's all okay.
Factory says, Cold weather 5W30 weight only. Hot months 10W30 weight. Do not use any heavier weight are it will destroy the valve train.
5W30 in the winter months / COLD. Anything heavier will burn the valvetrain up in time.