Originally Posted By: Bill in Utah
No. Unless the MFG says you have to run syn in the manual (turbo, etc) with a 3k OCI, you are wasting your $$.
Really if your 3k miles are in a short time, you are wasting conventional oil with only a 3k OCI.
Syn does not get oil to the parts any quicker than normal oil unless we are talking WELL below zero (like -30 to -40 BELOW)
A 5w-20 Conventional oil is the SAME as a 5w-20 Syn oil. Not thinner.
Take care, Bill
Bill, you always have sound advice on this board. I totally agree with your points.
When an oil is xW-xx it has to be whitin a certain range in terms of viscosity regardless if it's dino or synthetic. Synthetics may have more uniformed molecules but that doesn't make them "thinner", not in terms of viscosity anyways.