The higher the octane number is its ability to burn slower. Usually in stock production cars, higher-octane will in-fact give your car less performance. I did say usually because most production cars are built to run on current gas standards. A) Standards do change, notably when the US went from leaded to unleaded fuel, or in California with lower octane numbers. (The reason California has a lower octane number, is because the over compensating tree huggers who eliminated lead, found that the chemicals used to replace the lead are more than 1000 % worse for the environment). B) The NSX is a high performance car, and though it may live on lower octane, the optimal spec may be higher then what they advertise as necessary. The need for a slower burn is necessary when changing compression ratios, squish velocity, back pressure, heat or advancing the timing. Lead is the only known element found to bring levels over a true 104 motor octane. Many companies advertise 110+ unleaded fuels, but that’s research octane (Kind of like the wheel vs. crank HP), and some advertisers just outright lie. Most of these 110+ test at or below 101 octane. True 103+ octane unleaded costs about $8.50 a gallon, and has very volatile tune characteristics (Hyper temperature sensitive) and smells like Propylene or Nitro. If I needed higher octane I would run leaded fuels, (of course if it was allowed by the sanctioning organization). The best dyno tested unleaded fuel is Phillips 66 B42, and its relatively lower cost. Oh for those that don’t know race fuel numbers, leaded fuel can go over 118 motor octane for very high nitrous applications.
Rob
X-VP Fuel Distributor