High Octane gasoline effect on '91 NSX power

[classic cars]

AGIP has recently introduced a relatively low price high-octane gasoline in Italy. It costs only Euro 0.04 more per litre and has 98 octane vs 95 normal.
The idea is that modern cars have a pinging sensor, which detects detonation (or lack of it) and may advance/retard ignition to an optimal level, thus increasing torque and power if the octane rating is higher.
Now the question is: does my '91 NSX have the ability to tune the ignition point to match a better gasoline? otherwise can I assume using this gasoline is just a waste of money?
I did my "search" exercise, but could not find an answer...
Thanks

Mike

 

[MarkB]

The way I understand the operation of the EMS is: the engine will de-tune itself to aid in the reduction of pinging but only to a point. Using a higher octane than that for which the system was designed is basically a waste of money because, the system cannot increase compression and/or alter timing to make use of the increase.

 

[nsxtasy]

I have tried using higher octane unleaded gasoline at the racetrack - anywhere from 100 to 105 octane, instead of the 93* octane premium fuel in most of North America - and I haven't noticed any difference in performance. I agree with Mark; if you use less octane than specified by Acura (91 or higher), you will see a decrease in performance, but you won't see an increase if you use fuel with significantly higher octane than that in a stock NSX. If you have major engine modifications and the ability to customize your ECU to take advantage of the higher octane, that might be an exception; I don't know.

* Europe and North America use two different methods of stating octane on the pump. In North America, the pump is labeled with the antiknock index, (RON+MON)/2, where RON is the Research Octane Rating and MON is the Motor Octane Rating. For more information on octane ratings, see the Gasoline FAQ, available here and other places on the web. Regarding this question, it supports what Mark and I have said, by stating (in section 6.13): "If you are already using the proper octane fuel, you will not obtain more power from higher octane fuels. The engine will be already operating at optimum settings, and a higher octane should have no effect on the management system. Your driveability and fuel economy will remain the same. The higher octane fuel costs more, so you are just throwing money away. If you are already using a fuel with an octane rating slightly below the optimum, then using a higher octane fuel will cause the engine management system to move to the optimum settings, possibly resulting in both increased power and improved fuel economy."