the pre-burnishing factoid I got from a car and driver eons ago.. now can't find it when I need it.. go figure..

that said I copied this from the Mobil 1 website.. take it at face value they are marketing a product..


Myth: You should break in your engine with conventional oil, then switch to Mobil 1.

Fact: You can start using Mobil 1 with SuperSyn™ in new vehicles at any time, even in brand-new vehicles. In fact, Mobil 1 with SuperSyn™ is original equipment (it is installed at the factory) in:


Chevrolet Corvette
All Porsche vehicles
Mercedes-Benz AMG vehicles
Dodge Viper
Ford Mustang Cobra R
All Aston Martin cars

One of the myths that persists about Mobil 1 is that new engines require a break-in period with conventional oil. Current engine manufacturing technology does not require this break-in period. As indicated by the decisions of the engineers who design these high-performance cars, Mobil 1 with SuperSyn™ can be used in an engine from the day you drive the car off the showroom floor.

 

A synthetic oil is too sippery for break in. It won't allow the bearings in the engine to develop a wear pattern or seat properly which will more than likely cause them to spin.

Also, when the manufacturers put a motor together, they torque all the bolts at the same time to the exact same load instead of using a torque sequence. I mean every single head bolt is tightened at the exact same time to the exact same torque load. Same for the rods/mains/intake/etc... Obviously this isn't something you can do in your garage at home.

 

See this is what I don't get. Every time we have a synthetic vs. conventional oil thread- IE what to use in a used engine, all I hear is "well, synthetic oil is a little more slippery than conventional oil, nothing drastic, the advantage is that it doesn't break down and lasts longer". Then everytime someone asks if they can use synthetic in a new engine, all of a sudden it's "well synthetics are waaaaaaaay to slippery to use in a new motor". Come on guys, what is it.

 

I say it's a matter of preferences. If you want to use synthetic oil for break in, go right ahead. Myself, I'll stick to dino left overs for the first 500 miles or so and then switch. It's a free country (for the most part) do what you want.

 

I too would not use synthetic for break in hell I even think some regular napa 10w30 would be better than to use a synthetic.. Also partially why synthetic is "slipery" is because it contains small amount s of parafin wax which also wont help new bearings seat well