I have a 99 camaro ss 5.7 v8 with 150k. Going synthetic oil but want to know if putting a additive in my oil to restore and stop a small leak or to add life to the motor is a good idea and if it is which one is the best. What is the best one for fuel?
Additives are good only for those involved in selling them. They may only harm your oil by reducing or even canceling the effect of the built-in ones (you should know that modern motor oils are based on industry-grade additive blends carefully metered at oil production time). There is no way an independent additive manufacturer can know where its product will end up, so it's all just a big money-making operation. Additives, unlike cooling ones, cannot be used to stop oil leaks. Concentrate rather on using good quality oil, filters and make sure they are replaced as per car Manufacturer's specs, that's all there is to it. A similar story goes for fuel additives, except perhaps for the winter diesel one, which may be required in some areas.
If you have a oil leak I would recommend staying away from the synthetic oil until you get the leak taken care of. Sea Foam is a good product to use in the crankcase and in the fuel. But I know of nothing that is good at stopping a oil leak.
There is not an oil or fuel company that advises you put an additive in their stuff. Additives are made by additive makers and are advertised as being neccessary for whatever the additive was made to do. In short a good marketing firm could sell cow manure to a dairy farmer. Get my point?
