Are synthetic motor oils compatible with petroleum motor oils and other synthetics?
Yes, synthetic oils for passenger car and light truck use are fully compatible with petroleum oil and other synthetic lubricants. But, even though they are compatible it is best not to mix different brands of oil. Each brand of oil has a specific chemistry and additive package and two different oils mixed together may result in optimal performance as they were engineered to if the chemistries of the oil becomes offset by mixing with another brand of oil.
