Use German Engine Synthetic Oils or French
Never mix any additives to boost engine oil no way to go.
Use nanotechnology to treat engine metal only once a 50.000 km
Not use those magic engine oils like 5W50 or 10W60
Use only 5W30 or 0W30.
Worn engines burning every viscosities without any difference.
Tick oil damaging engines - very slow flow
Racing engines are built for extreme use big oil gallery and extream heat what allowed for use of very tick engine oils.
The engine needs a very fast flow of the oil to cool down and lubricating moving parts.
Not true. I see this nonsense all the time.
Racing engines use thin oils now to minimize friction. NASCAR is all 20wt due to very tight tolerances.
At mild ambient temperatures there is a negligible difference between a synthetic 10w30 and 0w30. Oils with a low winter rating don’t have any advantage until the ambient temp gets lower than 0F. If it’s liquid and pumpable at a given temperature they will both flow at the same volume. 5w and 0w also have undesirable characteristics like higher volatility and are susceptible to viscosity loss due to shearing. A 10w30 will not have any of these undesirable properties.
Older engines, air cooled or extreme use need thicker oils. If you have a a 20 year old car or motorcycle specced with a xw40 or xw50 use it as they have looser tolerances or higher thermal loads and need thicker oil.
Many great oils made in America. Some mediocre oils made in Germany (liqui-moly) and France. Redline, Amsoil, TGMO and RLI are all American and they arguable make the best stuff out there....
As far as additives go:
I believe dry lubricants like Mos2 found in LM2009 do help with cold and dry starts. After an oil film is established this effect is negligible.
LM ceratec was proven to reduce friction when added to conventional 10w30 in a small gasoline engine.
Prolong, Bestline and other Chlorinated paraffins have been proven to work in providing a durable anti-wear coating on engines, however there is also evidence that these products can become corrosive and damage an engine if left in the sump for too long.