... engine oil isn't KY or hand lotion, it doesn't make anything harder or softer 
So, you've tested that theory first hand?
First hand, second hand, and although it's getting fewer and far-betweener, when Mrs Stang is cooperative, even a third hand now and then....
Going back to the original question, I could have mistaken it, but I think he was asking about Z-max, Slick 50, and the other "anti-friction" horsepower and protection stuff. A little different than the high detergent and viscosity builders that can have some unique benefits, although I still think they are band-aids at best, and no place in a fresh motor with the right oil
Some reading, I found this on a net. It's am Amsoil dealer web page, which is good oil, but somehow can be a little cult-like itself LOL Nothing against the stuff, just odd how loyal the followers are sometimes. (Sorry if I offend anyone here, it is good oil)
It also addresses the "too much of a good thing" that FElony pointed out.
Federal Trade Commission Charges zMax with False and Deceptive Advertising
ZMax is the latest company to be charged in a long list of companies. (Read about the latest FTC charges against zMax in our informative articles links below). The FTC has successfully halted false and deceptive advertising by the marketers of Dura Lube, Motor Up, Prolong, Valvoline, Slick 50, STP and other major brands of engine treatment systems. Unfortunately, halting the deceptive advertising does not correct the false word-of-mouth advertising which continues to be spread by unsuspecting customers who don’t know they were originally lied to.
Without going into extensive detail here’s what you need to know about most aftermarket oil additives: There are basically two types of additives used, either Teflon based with PTFE (like Slick 50) or Chlorinated based (like Dura Lube) with some type of carrier, usually a paraffin based carrier or other mineral oil. Some have extremely large amounts of moly (or MoS2 – Molybdenum Disulfide), zinc or phosphorus: all are EP (extreme pressure) agents which are detrimental to a motor oils’ proper function in the amount that these additives use.
EP additives are great in gear lubes (where they’re widely used by the whole lubrication industry), but they typically cause increased friction, heat, and reduced fuel economy at the lower-pressure loads in an engine application. And at the higher operating temperatures that engine oils are subjected to, EP’s typically break down and cause corrosion of copper/bronze/brass components (bearings).
Teflon does absolutely nothing beneficial inside your engine. Teflon must be heated up to about 800 deg. F to get it to stick to anything for friction reducing purposes, just like the Teflon on a frying pan. In your engine what those suspended microscopic colloidal Teflon particles do is gradually attach to your oil pick-up screen and reduce oil flow to your critical components as well as reducing the oil flow in other critical internal engine passages by attaching themselves to the passageway walls. In addition, as your oil filter captures some of these suspended Teflon particles, your filter flow rate will be reduced with a higher pressure drop across the filter. The increasing restriction can gradually default more often into by-pass mode even at moderate temperatures and engine rpm’s, which means more unfiltered oil will be flowing through your engine. At higher rpm’s, some filters can collapse from the higher pressure differentials, starving your engine for oil and producing rapid engine failure.
Ever get bleach on your fingers? It’s pretty slippery isn’t it? Same principle here. Add enough Chlorinated components to a carrier and mix it with some type of teflon, moly, zinc or phosporus & you can reduce the friction, except for one “minor” thing: Chlorinated additives mixed with oil and subjected to heat form hydrochloric acid! Hydrochloric acid is extremely harmful to your internal engine parts. Get the picture?
That’s the summary picture. Bottom line is: When using a properly formulated motor oil you do not need any additives whatsoever and additionally, the additives you may put in can react negatively with the additives the oil company carefully blended in. Do yourself a favor and stay away from aftermarket oil additives, regardless of how appealing the bogus claims are in their advertising! Instead, use a high-performance synthetic oil that publishes their ASTM test data… instead of implying with a marketing-Jedi mind-wave “you don’t need to see our data”. (Yes, you really do.)
What if They Have a Test To Show How Their Additive Works?… Read On…………
At a trade show we attended, one of these miracle oil additive companies was there with a machine that demonstrated how their additive reduced friction. It was a motor with rotating solid steel disc secured to the motor shaft and a torque meter with a flat piece of steel mounted on the torque arm. They put every type of oil on the market, one by one, on the machine & pressed hard on the torque meter and at about 20-40 lb-ft torque the torque arm would stall the motor….that is, until they cleaned it off & tried their (chlorinated) additive “IXL” on the bearing & ran the test.
People were amazed as the meter peaked out at 140 lb-ft. torque and still didn’t stall the motor! We knew what was happening but many unsuspecting consumers were eating it up and standing in line to buy the additive! The next day we showed up with some Head & Shoulders Shampoo disguised in an oil bottle & had the IXL additive people try it on their test machine. The operator was amazed as the motor barely stalled at 140 lb-ft! The operator says that’s pretty good stuff, what is it? We said Head & Shoulders. He was quite embarrassed to say the least. Head & Shoulders has high levels of ZINC in it that attaches itself to ferrous metals. Coke soft drink will do exactly the same thing. ZINC reduces friction and provides anti-wear protection and is present in most motor oils at a much reduced level. Now, would you put Head & Shoulders in your engine?
