When mixed in a 60:1 ratio of
fuel to additive the STP averaged a RON reading of 100.1 and a MON
rating of 90.2. Giving STP in a concentration of 60:1 an AKI
of 95.2 when mixed with 93 pump fuel.
When used an a concentration of 20:1, over the recommended maximum,
103.1 RON was achieved with a MON of 93.5 giving it a AKI of 98.4.
As with almost all of the boosters tested, more than one bottle is
needed to raise the octane of an entire tank any significant amount.
Based on the amounts needed, boosting 87 octane to 93 is not cost
effective over just purchasing premium from the start. To boost to 98
AKI from 93 on most tanks would require over 6 bottles. This
level of additive is never recommended.
