Elevated combustion pressure contaminates the oil with blowby gases and promotes oxidation by raising crankcase oil temperature. That fraction of the oil diverted to the turbocharger can undergo 80°F temperature rise in its passage over the bushings. Change lube oil and filter(s) frequently.
The cost and disposal problems associated with filters make reusable filters attractive for fleet operators. Racor, a division of Parker Hannifin, manufactures a series of liquid filters with washable, stainless-steel elements and a TattleTale light that alerts the operator when the filter needs to be cleaned.
Frequently inspect the turbocharger and its oiling circuitry for evidence of leaks that, if neglected, can draw down the crankcase.