RWalker, I ran amalgamated (the TDR formula) 4 times always on a full tank and after about 1/2 tank used i would always develop a rough idle upon start up in the mornings or after letting the truck sit for 5 hrs, i could clear it by gassing it or driving aggressively for a couple of miles but the rough idle would always be back on first start up in mornings. The next tank with out amalgamated and running a bit of Sea Foam would clear the roughness to a smooth idle for the remainder of the tank (aprox 1300mi). Every time i used amalgamated i would get a rough idle i stopped using it after 4 tries and getting the same results. Could i have gotten a bad batch ???, i've run more than 20000mi with no additive and always a nice smooth idle, thanks for the help & info, James.