Mostly I'm referring to 87 Octane not 89. And its about 25 cents less around my way. I've used 87 octane and the engine diesels when I shut it off and knocks like a baby's rattle when I drive. (Although I got rid of the knock by strictly using premium 93 octane gas and dropping it down to 6-degrees BTDC).
One thing that I learned the hard way is that if one bores out the engine like I did and you don't install thicker head gaskets, detonation will be a constant companion regardless of ESC. There is no escaping using premium gas once you bore out the block and even with premium you'll still have to drop the timing.
It's not bad cause one saves gas but you can't ram the throttle and expect to go anywhere. It's peppier than an N/A but doesn't live up to the turbo myth.
Looking over those patents I figured out a way to make water injection work with my Q-Jet without spraying or those fancy expensive pumps. If I'm successful with my radical carb design I will share my experiment. If it works, I'll be able to use 87 octane and pull much more than the OEM 15-degrees BTDC.
