Well, it's 40-60% oil, and the rest is naphtha & isopropyl alcohol. I wouldn't use it as an additive with every tank, but used per the manufacturer's recommendation (every 2,000-5,000 miles, at a concentration of about 1 ounce per gallon), I don't think you're going to hurt anything over the long run.

The oil in SF isn't corrosive to any of the fuel system components, and compared to the levels of naphtha and alcohol that are already in your gasoline, the SF isn't changing the chemistry *that* drastically.

 

While hot spots can certainly be a factor, the compression concern is more significant!

Hot spots have to just in the right place to start an alternate flame front causing the two to collide.

High compression due to excess carbon when present, will have a repeatable effect on every compression stroke; hot spots will be more of a hit or miss.

As always, best way to tell is to measure the compression.

 

Although I use Techron in my cars and like the results, I have not used Sea Foam and BG. Would you rank them:

1) Sea Foam
2) BG 44K
3) Techron

I have heard good things about Sea Foam and BG, but I would like to know what the members thought.

 

The problem is, there's no way to use a compression test (where you stick a pressure gauge in the spark plug hole and crank the engine over) to quantify an increase in static compression ratio from carbon buildup. Too many variables affect the outcome of a compression test (how fast your engine cranks over, valve wear, ring wear, etcetera). That's why most service manuals specify a fairly wide range of compression values as being "okay", and tell you to concentrate more on differences between the individual cylinder values rather than the actual values themselves.

The only way to really measure the static compression is by taking the cylinder head off, measuring the head gasket thickness, the deck height, and the volume of the combustion chamber. But if you're doing that, you may as well just de-carbon the engine while you're in there.