Tell that to all the OFF and ON Road Truckers logging millions of miles on dino. I would venture to say neither protects better. If used appropriately and in accordance with vehicle specifications, either will protect virtually the same.
Originally Posted By: carock
There is enough information in this thread to finally answer the OP’s question. Does conventional oil protect better than synthetic? The answer is no. In every instance I can easily find, the only evidence people present to show that dino oil protects as good or better than synthetic is UOA metal wear numbers. I think we have established that UOA metal wear numbers are the wrong tool for the job. Unless somebody can show me evidence that a real world passenger car or fleet car test was conducted where dino oil proved it was superior to synthetic oil I think the case is closed. There are real world passenger and fleet car tests showing that synthetic oil is superior to dino oil. The other argument people have made is that dino oils are cheaper and it just isn’t worth using synthetics. That is not really the question.