What I was taught, was that synthetic oil molecules will not break down at high temp. like dino (dino generally doesnt break down in normal operating conditions). As far as cleaning and lasting longer, this has to do with additives, detergents and anti-acid additives. so, does mobil 1 syn have way more additives than any dino? I dont doubt it can lubricate better, but if all those additives get used up then the oil will be damaging to the engine no matter how superior the lubricating oil is. remember that lube oil can be recycled, the oil doesnt wear out, the additives get used up, carbon and acids. Anyone care to elaborate , disagree etc?