By accident, I put in 85 octane in my car that takes 87 octane, I have a question about this.?

bye some 104 octane booster at a auto parts store will help out right away just only use about 3/4 of the it on a full tank.will run good !

yes, but why run on low octane gas for 3/4 tank. just go buy some octane booster at a auto parts store (tell them what you did) and put some in and drive it a while and then put in some more till it smooths out. the 85 octane tank you bought it from may have water in it cause nobody uses 85 octane much anymore. you can also go to a mechanic and have him drain the tank and put in the right kind or, you could siphon out the gas yourself if you are handy with that and use it in your lawn mower or edger. other than that, just put in higher octane gas when you are a little low and should be okay. hope that helps.

Yup, you need to get some premium in there behind that cruddy gas. I did the same thing while travelling through Colorado. They offer 85 octane because of the thinner air in the high mountains, but 85 octane has such low power, the car will struggle hard to perform. It will burn up faster than 87 or 93 octane, because you need to work the engine harder to do the work it needs to do. My MPG fell from 33 mpg to 24 mpg until I used up the 85 and refilled with 89, whichis their premium grade. Take a 200 mile road trip to get rid of that crud. Your car will be back to normal after you refill with real gasoline. That 85 is unfit for lawn mowers. Good luck.

I didn't even know 85 octane existed... If there is a popping it is probably back firing due to using really cheap gas. How much did you put in? With the engine jumping around and backfiring, I really think you should consider siphoning the fuel out and replacing it with 87.. Where did you find 85 octane gas?

fill it up with a higher octane as soon as possible yes 91 or 93 even a quarter of a tank should bring it up enough, you can burn up an engine having too low of octane but not too high

you could also try a bottle of octane booster if the tank is full this is the fastest option u can buy a bottle at any part store and they dont cost much