I was reading the SAE article presenting the Mobil1 "Aunt Minnie Test", and came across this statement that I'd like folks here to explain to me (page 766 of the original publication): "...the lower detergency of Syn E (7.2 TBN) vs. Syn F (11.8 TBN) appeared to have some effect on piston cleanliness in side by side testing in the 2.0 L 4 cylinder engine. The vehicle running on Syn E gave an average piston varnish of 6.2 compared to 8.1 for SynF." Syn E and Syn F are two different synthetic oils used in this test.
(1) The authors of this study are talking as if it is reasonable to expect a higher TBN to allow an oil to clean up more varnish on the pistons, correct?
(2) The piston scores are higher is better, correct?
I have always thought of TBN as simply reducing acid, and in turn, the likelihood of acid corrosion.
(3) But these authors are suggesting that it also will fight deposits, or have I read too much into their statement?
(1) The authors of this study are talking as if it is reasonable to expect a higher TBN to allow an oil to clean up more varnish on the pistons, correct?
(2) The piston scores are higher is better, correct?
I have always thought of TBN as simply reducing acid, and in turn, the likelihood of acid corrosion.
(3) But these authors are suggesting that it also will fight deposits, or have I read too much into their statement?
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