There seem to be three schools of thought on what the minimum TBN for a UOA should be before the oil is changed as follows:
1/ Backstones > 1
2/ Various experts > 3
3/ Some oily document > Half of the VOA TBN.
I use no 2 and would not use my Synthoil below a TBN of 3, but I would be interested in what other folks use as a minimum figure and why.
I like Blackstones, but they do seem to be rather keen on extending OCI's and once an oil shears it is the additives that save the day.
1/ Backstones > 1
2/ Various experts > 3
3/ Some oily document > Half of the VOA TBN.
I use no 2 and would not use my Synthoil below a TBN of 3, but I would be interested in what other folks use as a minimum figure and why.
I like Blackstones, but they do seem to be rather keen on extending OCI's and once an oil shears it is the additives that save the day.
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