Today I stumbled upon a small stash of UNused oil in bottles that had no date code on them but did have the SAE API circle with ratings of SD and SF.
I thought that I was told that the higher in the alphabet the second letter was, the higher the detergent level.
In short, an oil like this:
...with it's SN rating is a MUCH higher detergent oil.
If this is true, what other characteristics could be said about this older oil? Is it possible that it may have a higher Zinc count as well?
I ask because I suspect that as the oil market adjusted to meet new car emission standards, they also included roller lifters that didn't need the cushion effect that was crucial for flat tappet engines.
I have 20 quarts on unopened "classic" oil that have either the API SD, SF or no rating at all. The oldest oil that I got is in cans!
I don't intend to use this in my stroked 440/495 car. I use "Driven" oil simply because of the stiffer valvesprings and solid lifter cam.
I have a few other lower performance flat tappet cars out back that may benefit from an older formula of oil. They do all have softer valvesprings which probably saves the lifters and camshaft from excessive wear.
What say you? Do you think the lower detergent oil may carry a higher amount of Zinc/ZDDP ? How would it even be determined without an oil analysis?
My thoughts are that this oil wouldn't hurt but might be a bit better than off the shelf NAPA or O'Rielly oil...maybe even better than other other new oils with the higher detergent levels.
I thought that I was told that the higher in the alphabet the second letter was, the higher the detergent level.
In short, an oil like this:
...with it's SN rating is a MUCH higher detergent oil.
If this is true, what other characteristics could be said about this older oil? Is it possible that it may have a higher Zinc count as well?
I ask because I suspect that as the oil market adjusted to meet new car emission standards, they also included roller lifters that didn't need the cushion effect that was crucial for flat tappet engines.
I have 20 quarts on unopened "classic" oil that have either the API SD, SF or no rating at all. The oldest oil that I got is in cans!
I don't intend to use this in my stroked 440/495 car. I use "Driven" oil simply because of the stiffer valvesprings and solid lifter cam.
I have a few other lower performance flat tappet cars out back that may benefit from an older formula of oil. They do all have softer valvesprings which probably saves the lifters and camshaft from excessive wear.
What say you? Do you think the lower detergent oil may carry a higher amount of Zinc/ZDDP ? How would it even be determined without an oil analysis?
My thoughts are that this oil wouldn't hurt but might be a bit better than off the shelf NAPA or O'Rielly oil...maybe even better than other other new oils with the higher detergent levels.
