Is it un-healthy if i use 87 octane for my b16 motor ive been useing 91 octane for about 6 months.

 

a answer from a wise man would be nice

 

Its not good to run a low octane gas on a high compression engine such as a b16a. You can run it though. I tried one time with my b16 and it idled like crap and hesitated under a lot of throttle.
Just run premuim. Youll hate how the engine will run on 87

 

you can run 87 octane but I would not rev the engine too high because detonation might occur because of the high compression.

 

I got much better times at the quarter mile using Sunoco 94 instead of Mobil 93 (I've ran over 100 times that year, so I know exactly what affected my car in what way) ....probably because of the tune of the japanese b16 computer...I don't know.

Just something to think about. If anything, test how fast your car is with 91 and 87, you'll see the difference yourself.