I had came across this product several times before and never gave it a shot because I didn't know much about liquimoly before. Until few weeks ago, a buddy of mine bought a BMW M3 and he asked me what oil he should change. If any of you knows M3s, you should probably knows the rod bearing issue they have. Because of this M3s basically have to have 10w freaking 60 oil in their motor… or 5w40 if you drive in winter… Since I hate Castrol and Mobil is not that good anymore. I found liquimoly while I search on the bimmer forum. I soon to find out that it is actually the best oil brand in German and their liqui-moly is one of the proven working friction modifier beside zinc. Their oil is probably the best oil for M3s period. So my buddy bought the 5w40 oil only and I bought 2 cans of this to mix with Amsoil for my Mustang GT and my girl friend's Sonic.A week after the oil change, my buddy told me that he did notice that the oil temperature raise a little faster compare to 10w60 but that should be expected since 5w40 is much thinner. Other than that, it's too early and very hard to tell a difference by changing from a full synthetic to another full synthetic. I will wait until the next oil analysis to see if there is any improvements. On the other hands, for my Mustang and my girl's Sonic. Oh man, what a great difference this product made.First, I change oil on the Sonic and pour this terrifying looking liqui-moly into the engine. (I got to say it scare the s**t out of people that were watching me doing the oil change lol) Then I start the car, walk up to the front of the car and try to listen if there is any decrease in noise the engine made. Unfortunately, Sonic's motor is chain drive, which is very loud and there is nothing you can do about it. So I reseted the car's MPG, returned the car to my girl and asked her to drive car like she normally drive. The result was very well. Sonic's MPG raised from 31.8 (should be lower, because she drove 6 hours on highway before the photo was taken) to 33.8. More than 6% increase in MPG sounds very good to me, well worth the money I spent on the product!Now for my Mustang GT, the difference is huge. This 5.0 coyote engine can be loud at idle. It's V8 after all. However, as soon as I pour this magic moly in the engine and start the car. Oh man, what a whisper quite engine it became (beside the Borla exhaust anyway lol) I mean literally all the lifter noise and the metal clapping sound was gone. All I can hear is the engine is running smoothly and pulling air in the intake. Heavenly music to my ear. I showed it my buddy and he was amazed as well, but we both agree that we should better not add anything in those BMW engine though… Who knows what can went wrong if you know what I mean… Anyway, I was sold on this product. I'm glad that I found something that it's indeed not a snake oil. I may try the cera tech next time as well. Good job Liquimoly.