This Napa Platinum on a 2001 Firebird 3800, OCI was 3k and 2.5 years, changed when the change oil light came on. This car isn't used that frequently (just over 1000 miles a year), and most driving is local.
Date code is 100518 (October 5, 2018). Classic Wix construction, and a coil spring.
It had a lot of oil in it. Remember, there is no bypass valve, as the bypass is in the block as typical for older GM cars.
Oil used was Rotella T6 5w30 and a half quart of Napa synthetic (Valvoline) 5w30.
It was replaced with a Fram PH3387A orange can and Rotella T6 and ST syn 5w30
Date code is 100518 (October 5, 2018). Classic Wix construction, and a coil spring.
It had a lot of oil in it. Remember, there is no bypass valve, as the bypass is in the block as typical for older GM cars.
Oil used was Rotella T6 5w30 and a half quart of Napa synthetic (Valvoline) 5w30.
It was replaced with a Fram PH3387A orange can and Rotella T6 and ST syn 5w30