My 2 cents worth. If you believe that an additive will fix a mechinical problem, use it. I use wd40 when ever something does not work. About 1/2 the time it works. Door knobs, locks, garage openers, etc. What the he**, I want to do something else, and it buy you some time. Makes you look like you really know what you are doing. I usually schedule a repair and usually find the real proplem.The only additive that I use, gasline freeze,nothing more than alcohol to mix with the water in the tank and burn it.The other is water pump lub to extend the life of the water pump when you do not change the anti freeze.
The old mechanic I worked with (1956) had problems with old engines when the detergent oils came out. He would change the oil and filter,use a mixture of 20W oil and solvent. Run the engine for 2-3 minutes and letit set for 30 60 munutes, all the gunk run into the pan. Drain the oil and replace the filter and use 20W oil. Have the owner return in 500 miles and change the oil and filter. This makes more sense than all the additives.It removes the crude in the motor and the detergent oil will keep it clean.
