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Removing the sulfer and aromatics to single digit parts per million results in better oxidative stability. Waxes, per se, are actually great lubes - in their liquid state. Their problem is that they crystalize out at relatively high temperatures compared to true oils, so cold weather operation becomes problematic because of gelling in the sump. Don't confuse "paraffin" with "wax". "Paraffin" is a type of organic compound, not a specific substance. "Waxes" are only one sub-category in the extensive list of "paraffins". Simultaneously, concentrating desirable paraffin base lube stocks in the entry volume results in higher quality base lube stock due to higher viscosity indexes (greater inherent viscosity range requires less VI improver additive).