I agree, all this talk about 5W30 vs 10W30 vs whatever is for another topic, this thread is about synth vs dino oils

 

It is important to remember that dino comes out of the ground and refined. Refined means removing the "bad" stuff. Bad stuff is wax, tar, etc. that has potential to contribute to deposits in your engine. Dino is probably perfectly fine if you change it every 3000 miles.

Also, it is important to consider that M1 and other high end synthetics may have better dispersant and detergent properties. They are designed to capture and retain contaminants so that they remain in solution with the oil and do not deposit on the engine surfaces. It could be that the M1 was just better at keeping the analyzed elements with it so they could be flushed out and analyzed.

I just have personally seen valve covers and oil caps on engines that have run Pennz for the majority of the time. They almost always have a waxy white residue accumulated on them. I'm happy that the wear numbers look better, but I would be concerned about cleanliness over the long haul.

 

My personal interpretation of the marketing claims on synthetics is that these oils have better stability properties, higher consistency, less foreign material, flow better at lower temperatures. They are also easier to reach the multi-grade ranges with more base adjustments rather than relying more on higher amounts of additives (these thinning preventing additives are first to breakdown, have to lubrication properties). That most likely means that synthetics provide better sludge protection, last longer, especially if you widen the grade range (ie 5w30). It is impossible, however, to have an opinion on their lubrication performance in regards to friction related wear out (when compared to dino fresh oil) and on their potential for higher solubility of engine alloy/metals especially at high temperatures.

For long distances/few cold starts 10W30 dino/3750mi changes seems to me more than enough protection at a low cost (I do my own oil changes). For multiple cold starts, however, my preference is 5W30 and when the cold starts come with traffic idling I think overall the 5W/30 synthetic is a better choice (higher stability and higher amount of lubricating base/less additives). Well, provided that we don’t see a lot more of oil test date suggesting that synthetics like M1 may solubilze metals easier or that they are inferior friction protestants.

Sorry I cannot offer an expert opinion.

 

One thing for sure, the debate will not be solved here. But it should be noted that synthetic base stocks were developed for a reason. And that reason is because of the limitations of petroleum based lubricant properties.

On top of that, the potential extention of service intervals from synthetic almost bridges the gap in cost in raw materials alone. When you add the labor time to do dino twice as often, you are surely money ahead by using synthetic.

On the other hand, if people want to put something that was once in the dirt in their engine, thats cool. Most food comes from there so why not? Whats good for the man must be good for the machine I guess.

 

My understanding is that it's a bit of a myth to believe that using a heavier than recommended viscosity for everyday driving offers better protection. In fact, because of the typically shorter warm-up times and frequent re-starts, a heavier oil can be harder on the engine as it flows less easily. Also wastes a bit of gas.

This isn't the rule of course with heavily modded engines, nor for special driving conditions.