So one of the gas stations by my house had broken pumps, and it was selling 91 octane at 87 prices. So I thought, "what the hell." I normally get about 28mpg combined in the summer, and it drops to 25 in the winter, but during those couple of weeks in January on premium, I clocked in the lowest I've ever seen: 19.4mpg. I didn't even feel any extra power. Definitely not doing that again, but has anyone else attempted putting super in a car that didn't require it? Did you see similar results?

 

Octane is resistance to burn.. so I could see that. Especially if you are having weak spark issues, etc. My accent didn't seem to give a crap when I tried it.

 

It shouldn't go down noticeably. I'd be suspicious of any gas station's QC if they can't even charge the correct price.

 

In my experience when the car was OEM there was no difference, once modified there was.

 

Didn't make a difference on any of my stock cars.



Btw, likelihood to detonate =/= ease of ignition.