Ive used Seafoam on used cars before and I know they do make a difference on older cars. But for new ones, do they actually have any real benefit? Maybe something like preventing gunk from building up?
Seafoam is used to clean the fuel system when added to the fuel system.
I use it on my 94 Honda Magna Motorcycle once a year to keep the carbs clean. I also use Techron as well. I would not use any of these products on a modern engine using direct injection. I would worry about it causing damage to the injectors. I would never add anything to the oil that might thin the oil and cause problems with the valve timming control valves that could cause engine damage and void your warrenty. Just my two cents. I am a journeymen mechanic retired.