Think I'm gonna copy the following and paste it in every time some one mentions oil additives ......
Not bragging, just a matter of fact that I work for 1 of the top 4 major oil companies in the world. I work within sales and marketing for lubricants
which includes engine oils of every description.
Engine oils have a carefully blended balance of additives, any where up to 15, to give maximum performance. Most major oil companies will develop an engine oil in conjunction with engine manufacturers. We then run engine trials to gain manufacturers approvals .... note approvals and not meets manufacturers requirements ... big difference.
These engine tests alone can cost in excess of £50,000 per test.
So, after we (Big Oil) have spent a few £100 thousand developing and approving an engine oil someone comes along a drops in can of additive worth £20 and expects it to improve the oil
The oil company that made the oil, and the engine manufacturer that tested the oils did not include the additive in the blend, tests or approvals.
Just stick to a quality major brand of oil, that meets the right specifications and claims manufacturers approvals.
Please don't go adding "snake oil" to a decent engine oil ... it does not need it.
OK, time to get off my high horse.