I realize I might get a few insults hurled my way about how I could've destroyed my engine with snake oil and I've lost my mind as evidenced by the placebo effect I'm describing below, but I was previously running 5w-20 Havoline High Mileage in my Focus and when time came to change the oil, I grabbed some 5w-20 Valvoline Nextgen Conventional out of the stash to use. Prior to draining the oil, I ran a bottle of Gunk High Mileage Engine Flush through the engine and let it drain until there was pretty much no drips coming out. Well, the oil change itself was pretty uneventful, but there are a few good things I've noticed since changing the oil. 1) The engine turns over faster during startup. 2) Upon cold startup, I no longer hear any tapping noises. There was a light tapping noise I'd hear that would go away once the engine warmed up. 3) My highway gas mileage has increased from 31mpg to 32mpg. 4) The car has a manual transmission and I notice less drag when taking off. To describe it in more detail, I don't have to leave my foot on the clutch as long anymore because the engine doesn't bog down as it once did. I can come off the clutch much faster than what I was able to. 5) The engine already ran smooth, but it just seems to have smoothed out even more over the past 2000 miles or so since going with Nextgen. When I pull up to a traffic signal, the car idles noticeably quieter with less vibration than what it previously did. As far as why I decided to use the engine flush, the engine has varnish and out of curiosity, I wanted to see if the engine flush would do anything with regards to that. It was a one time deal on using engine flush. The varnish seemed to be slightly lighter after the flush (not enough to go wild over), but that could be just me wanting to see something better since I paid for a bottle of engine flush. I noticed that the Nextgen definitely was thinner than the Havoline High Mileage when pouring it out, so that could be why I'm noticing these improvements. Aside from me being out of my mind for using snake oil (I'm sure someone will imply that), what are your opinions about about my observations above? Is Nextgen just that good or did the snake oil provide any real benefit? Or is it a combination of both?