The temperature range the oil is exposed to in most vehicles can be wide, ranging from cold temperatures in the winter before the vehicle is started up, to hot operating temperatures when the vehicle is fully warmed up in hot summer weather. A specific oil will have high viscosity when cold and a lower viscosity at the engine's operating temperature. The difference in viscosities for most single-grade oil is too large between the extremes of temperature. To bring the difference in viscosities closer together, special additives called , or VIIs are added to the oil. These additives are used to make the oil a motor oil, though it is possible to have a multi-grade oil without the use of VIIs. The idea is to cause the multi-grade oil to have the viscosity of the base grade when cold and the viscosity of the second grade when hot. This enables one type of oil to be used all year. In fact, when multi-grades were initially developed, they were frequently described as . The viscosity of a multi-grade oil still varies logarithmically with temperature, but the slope representing the change is lessened.  This slope representing the change with temperature depends on the nature and amount of the additives to the base oil.
I ran mobile 1 15-50 synthetic through my Ninja 500 after reading an article ( in a motorcycle magazine no less) on how this oil outperformed motorcycle oil in a bike.
Breakdown of VIIs under shear is a concern in motorcycle applications, where the may share lubricating oil with the motor. For this reason, synthetic oil or motorcycle-specific oil is sometimes recommended. The necessity of higher-priced motorcycle-specific oil has also been challenged by at least one consumer organization.
Not all motor oil is created alike. In fact, different motor oil is required for different engines. Today we will look at the difference between two cycle oil and motor oil.