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The low-temperature pumpability of engine oil throughout the engine at startup is an important property. Insuring that fresh oils can be pumped at low temperatures has been a requirement of crankcase lubricants for approximately two decades. Extending the assurance of the oil's low temperature pumpability as it ages under engine operation has been the concern of car manufacturers and lubricant marketers for some time. In order to determine the factors influencing the aged oil's low temperature pumpability, we have undertaken a fleet test. We found that as lubricants are aged, excellent low temperature pumping properties can be maintained if lubricants are formulated with viscosity-index improvers incapable of forming polymer networks, base oils with a low tendency to form wax networks, effective pour-point depressants, and if oil drain intervals are not extended beyond the performance limitations of the specific lubricant category.

Friction reduction in lubricated components through engine oil formulations has been investigated in the present work. Three different DI packages in combination with one friction modifier were blended in SAE 5 W-20 and SAE 0 W-16 viscosity grades. The friction performance of these oils was compared with GF-5 SAE 5 W-20 oil. A motored cranktrain assembly has been used to evaluate these, in which friction mean effective pressure (FMEP) as a function of engine speeds at different lubricant temperatures is measured. Results show that the choice of DI package plays a significant role in friction reduction. Results obtained from the mini-traction machine (MTM2) provide detailed information on traction coefficient in boundary, mixed and elastohydrodynamic (EHD) lubrication regimes. It has been shown that the results from the cranktrain rig are fairly consistent with those found in MTM2 tests for all the lubricants tested.