Requirements for modern internal combustion engines are lower emissions, higher power density and longer maintenance intervals. These trends increase the demands on engine components, including lubricants. In a field study of petrol and diesel vehicles, oil condition of 47 engine oils from 12 vehicles are correlated with fresh oil properties and operating conditions, i.e., trip length and speed. Long-range petrol vehicles displayed accelerated chemical oil degradation compared to diesel vehicles. An explanation for this behaviour is assumed to be the difference air-to-fuel ratio. Short-range petrol vehicles showed an even faster oil degradation and significant changes in oil viscosity due to fuel dilution. Diesel vehicles exhibited higher soot loading and more pronounced engine wear indicated by iron content in the oils.

现代内燃机的要求是降低排放，提高功率密度和延长维护间隔。这些趋势增加了对包括润滑油在内的发动机部件的需求。在汽油和柴油车辆的现场研究中，来自12种车辆的47种机油的机油状况与新鲜机油特性和操作状况（即行程长度和速度）相关。与柴油车辆相比，远程汽油车辆显示出加速的化学油降解。假定对此行为的解释是空燃比差异。短程汽油车显示出更快的机油降解，并且由于燃料稀释而使机油粘度发生了显着变化。柴油车辆表现出较高的油烟量和更显着的发动机磨损，其表现为油中的铁含量。