Recent research on low HT/HS oils showed oils using salicylate detergents showed higher TBN retention even with lower starting base numbers .
Also the test oil with salicylate's and low low phosphorous outperformed the sulphonate oil with much more sulphur and phos in the anti-wear capability .
BTW ,I'm talking PCMO's here and not the oils typically associated with salicylate's in the formula .
Hint - Have you smelled your oil lately ?
Research Environment-Friendly Oils of Ultra Low Viscosity