[regor]

I've been happy with Tufoil. Been using it for 20 years or so. Never had any problems with my vehicles. Always noticed a lower RPM and higher MPG. When I had my 98 Dodge Ram, I had the infamous engine knock. This knock was so bad, it sounded like two sledge hammers hitting each other. Dodge said nothing was wrong and the noise wasn’t hurting my engine. For whatever reason, it wasn’t until the Ram hit 40,000 that I put tufoil in, within 1-2,000 miles, the knocking was gone. Sadly, or happily, Dodge was forced to buy back the Ram (Lemon Law) and that was it.
I use Mobil-1 in all my vehicles, probably just for that added protection. I also tend to put some Marvel Mystery Oil in my fuel tank every other fill up. I will stick a can of B-12 in the fuel tank 1 fill up before my oil changes.
Probably 25 years ago, a friend, whose father was a manager at a local Pep Boys, convinced me to buy a fuel catalyst called “Propel”. I wished another “real” fuel catalyst, such as Propel, which you added to the fuel tank, would come out.