Originally Posted By: Shannow
Originally Posted By: tig1
Originally Posted By: Gebo
Originally Posted By: motor_oil_madman
They tend to change formulations every few years, so using the same oil isn't really possible.
I'm impressed. Excellent point!
The OP ask about one brand of oil, not the same oil.
Well with the changes in basestock, additives, formulation, specification, and the J300 changes in the meantime, the "label" is virtually meaningless, isn't it ?
Your M1 of today is nothing like the M1 that you started with.
OP, sticking to the same "brand" for a quarter century means that the engine experiences changes in all the bits that matter (for the same viscosity grade), so I there's really no performance benefit.
And IF the formulation stayed the same for a quarter century, then whatever shortcoming it had would be highlighted oer time.
I wouldn't base this on a belief the oil chosen will never change formulation, that's a given. The choice is made because the consumer trusts a brand will keep up with industry standards, maintain a level of quality, can find what they need without hassle, prices are within reason of competitors and so on. Now, don't misunderstand me either... if i find an unbelievable deal on any 5W-20/30 synthetic while walking into AZone during their December clearance, I will bite. But Valvoline usually has one or two flavours involved in those clearance sales as well.
...and never had a bad UOA using any oil, really.