You can mostly ignore the HP data from the AP-22, it wasn't set up with the exact vehicle weight at the time - that's why I went to the dyno (see this thread for details). It's possible that at 90mph, the engine is past the 4600rpm power peak but not yet shifted into the next gear, which may explain the drop in power. Next time I use the AP-22, I'll set the weight, and compare those HP readings to the dyno readings.


Despite the mfr's claims, additives really won't add power by themselves. They may just clean out a dirty system, or help combustion if the engine is less than perfect. (?) But on a good-running engine, additives will do little if anything to make power. A couple percent gain is within the tolerances of the dyno, barely measureable. You can't easily put BTU in a bottle and increase the BTU content per gallon. You need either more fuel injected, or fuel that has a higher BTU content to begin with. Something like this syndiesel should make more power than plain #2, because of the higher BTU content. I think it's more like 10% higher, not the claimed 20%, but anyway.... the cost is insane. I am sorely tempted to try 5 gallons at the dyno & dragstrip after I get my final engine configuration completed (intercooler, etc), just to prove how much is gained with high BTU fuel. I'm a year or three away from that stage though.

Remember that cetane is like octane... once you pass a certain level, adding more does nothing but lighten your wallet.

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