Back in the days of leaded fuel, yes the mixture of 50-50 or so would bump the actual octane. I would mix Av gas and regular leaded and get higher octane than just the 110 low lead av gas.
Now days av gas would be nice, but it is expensive and "legally" to run it on the highway is verboten. No road tax is paid on it.
So one thing that I usually think of about the time I am fueling up with something other than regular. So the bloke before me used regular, I am paying for a higher grade from the time the pump starts pumping. So how much regular am I getting before I get the good stuff? I mean shoot there must be half gallon in the hose and pump of regular.
Puc- I had cars with the dash pot and later the anti-diesel solenoid, which worked better imop. But the easiest way was to just leave it in gear, kill the switch and let clutch out. That definalty killed the motor.