Adding Seafoam to the gas is a good way to keep the fuel injectors etc clean. I think they recommend a can per tankful or similar. You can also add it to the oil but be careful. They recommend only adding a few ounces to the oil; something like 1 ounce per quart of oil that it takes. The 2000 Camry takes 3,6 quarts so if you put in 4 oz you should be fine. Seafoam says that you can leave it in your oil indefinitely but most recommendations I've seen say to keep it in only about 200 miles of driving before your oil change which is what I did last time I changed the oil. The reason for being careful with the oil system is that you have to be wary of old oil seals getting affected and leaking.My wife's 2000 Toyota Camry has over 185xxx miles. Should I use some SeaFoam fuel additive? The car runs fine, I just imagine there is quite a bit of carbon build up with it being a high mileage car. Thoughts?
I realize that others have used it differently and added a lot more of it to both their fuel and oil without a problem but without a way to actually inspect the results on the internal engine parts including the seals and gaskets, we don't have much evidence of any claim made.