regular motor oil

regular motor oil

[′reg·yə·lər ′mōd·ər ‚ȯil]
(materials)
A petroleum lubricating oil suitable for use in internal combustion engines under normal operating conditions.
References in periodicals archive ?
The synthetic oils are better oils because they cause less wear on the engine, but they're twice as expensive as regular motor oil. I don't use synthetic oil in my own cars or on customers' cars, unless they specifically ask for and are willing to pay for the synthetic oil.
From a serviceability standpoint, most of the machines use regular motor oil in the engines, the transmissions, the brakes.