ATF has lots of Phosphorus Phosphorus can destroy the catalyst in the catalytic converter, if one exists on the vehicle.
I would recommend Gumout Regane as a fuel injector cleaner. Make sure is says Regane on the Bottle, Wally world has it for fairly cheap.
Regane, Redline SL-1, CRC guaranteed to pass, 3m Fuel system cleaner, Techron, all have a good quantity of Poly Ether Amine Some others too I cannot remember. PEA is proved to clean deposits without leaving any of its own. PEA has a distinctive fishy odor.
Marvel Mystery oil added to the gas acts as both an upper cylinder lubricant and cleans carbon deposits, and lubes the fuel pump too. No more than 4oz in 10 gallons of fuel.
2 stroke motor oil, TC-W3 rated, is an another fuel additive praised by many for cleaning and keeping combustion chambers and fuel systems clean. No more than 3Oz per 10 gallons of fuel.
I think the Lucas fuel additive and their power steering Stop leak are their only products worthy of consideration. Their oil stabilizer is absolute junk. Do not ever add this to a healthy engine. All it does is thicken the oil, and deplete the additive package of the motor oil it is added to, as it has NO additives of its own. No detergents, no extreme pressure additives, no friction modification, no disperants, nothing. If you want thicker oil, buy thicker oil, Do not buy that junk. LOS also reacts badly with some motor oils causing them to get foamy. You do not want foamy oil pumped through your bearings. Please avoid this well marketed product. It is only good for raising the oil pressure in heavily worn engines.
Seafoam is mostly alcohol and a pale oil. There is so much ethanol in our Fuel today, I will personally not add any more alcohol to it, no matter how well the product is praised on some online forums.
Some claim MPG improvements with MMO or TC-W3. they say on older engines the upper cylinder lube helps the piston rings to seal better for higher compression and more power and efficiency.
As long as one does not overdose on them, they won't do any harm, but they might not do any good either. GotSmart is not alone in his assessment that an upper cylinder lube has benefits, and The lucas does have another chemical inside of it that is said to promote more complete combustion.
I've tried them all and never could say any of them helped my MPG, and some of them hurt it if I overdosed the gas with them
