Dealer put ZAK C500 engine oil booster in my car with oil and filter change. This was a complimentary oil change that is included with an L Certified car.
I can’t imagine my engine needing this stuff added to 7.5 quarts of full synthetic oil. Think I will decline this stuff if/when I go in for my next oil change that I will have to pay for.
Oil level is about 3/8” above the full level on the dipstick. I was always told not to overfill a crankcase because the crankshaft tends to stir up the excess oil into a foam. Maybe that’s not true with our engines.

 

Foaming will happen in any engine but the oil level has to be way over filled. I've yet to see any tests showing additives reducing friction (they often make it go up), there are potentially other benefits like reduced oil burning and leaks. Auto makers are very sensitive to fuel economy across their fleet as well as performance if specific additives really did help then they would be in motor oil.

 

Yeah, overfilling can cause excessive aeration of the oil will lead to decreased lubricity and possible bearing failure. Having said that I have an Acura TSX racecar with a K24 and we over-fill the oil by 1/2 to 1 qt. in order to protect against oil starvation in corners, because we have to run the stock oil pan. ¯\_ (ツ)_/¯

Theoretically oil additives do add protection to your oil, but brand name synthetic oils already usually have additives in them so the benefit may be just theoretical/psychological. 3/8 inches isn't too bad they probably just put a full 8 qt in. If it were me, I'd probably crack the drain bolt myself and get the oil level correct. But the dealer should of filled it correctly to start with.

 

I suppose Lexus is paying for this stuff.
Dealer must make thousands of dollars a year on this if they are selling it with every oil change.
Ford says not to use it. Guess I need to look at Lexus owner’s manual.
Reminds me of Motor Honey that I would put in my oil burning ‘46 Plymouth when I was in high school.