Can you mix regular oil with synthetic oil?

Answer by  Brandon55 (1719)

No you cannot mix synthetic and regular oil. The synthetic creates a barrier on all moving parts which the conventional oil cannot pass through. A 50/50 mix would cause your engine to only utlize half of the oil which is bad no matter what the vehicle. In addition, foam and or gel can form.

Answer by  tyler (60)

Synthetic oil and regular oil can be mixxed. Companies sell oil labeled as "synthetic blend" which has both conventional and synthetic oil. Make sure they are the same weight.

Answer by  aeturnus (474)

Synthetic oil can be mixed with regular oil, but it is a tricky procedure. When mixing, the correct combination of each must be applied. If applied properly, it will give benefits of both synthetic and regular oil. If not, there may be minor problems. It is advisable to make sure that the weights are the same.

Answer by  Amber40 (24961)

You should never mix synthetic oil with regular oil in the same way you should never mix different weights of oil. If you added the regular oil to the synthetic it would pretty much eliminate the benefits of using the synthetic and could caused unwanted oiling issues. Play it safe and add the same kind in.

Answer by  les59 (852)

You can do this once or twice and get away with it. This is because sticking with one type of oil is only recommended. It can cause knocking though, repeatedly.