26 years and 270K in a Corolla, any oil I can find in 10w30 or 5w30, mostly synthetic for 7500 OCI, a puff of startup blue smoke before I crushed it for cash.
24 years and 270K in an Integra, any synthetic I can find in 10w30 or 5w30 for mostly 7500 OCI (a couple 10k), some leaks, some oil burn, engine rebuild twice due to radiator (CSF all metal) and radiator cap (Stant) problems.
13 years and 110K in an IS250, any synthetic I can find in 5w20 to 10w30 for 7500 OCI, burn 1 quart since new, at 8 years and 70K piston replacement due to carbon deposit by Lexus as TSB.
10 years and 110K in a Taurus, any oil I can find in 5w30, mostly synthetic for 7500 OCI, nothing wrong with the engine when dad trade it in for a Mazda5.
I don't stay loyal to any oil brand because their formula changes all the time. Same grade API oils have more similarity within their rating but different brands than say Pennzoil / Valvoline / Mobil within their brand but going from SL to SM, SN, SN Plus, Dexos 1, Dexos 1 Gen 2, etc. So I have no way of using the same oil over 20 years anyways.