A simple soak in the additive/gasoline is only 1 aspect of the effectiveness of a fuel additive. Not to mention, a spark plug will never be exposed to the fuel additive mix in this manner. One would have to pull the spark plugs, then fill each cylinder up with the mix, and then screw in the spark plug so it is submerged in the additive fuel mix
Ranking cleaners on this solely, makes the advice comical at best.
The other key component is residue after combustion, which is why BITOG loves PEA so much.
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back to BG products. BG also offers a supplement protection warranty when you use certain products in a new car, such as their MOA.