Car engines usually have a recommended octane rating and a minimum octane rating. If your car recommended gasoline is 91, 89 should be over the minimum, and since you only put two gallons, you have something about 90.5 (or higher) in your tank.
As long as you don't keep gasoline under the minimum, no damage will be made. The engine will have a bit less power, fuel economy will be reduced somehow, and throttle response will be slower (that's the part I hate the most), but it will be fine. If you don't like the way it runs, you may add a couple of gallons of 93 and everything will be solved.
Two gallons of 89 plus two gallons of 93 make four gallons of 91. That's more or less how fuel stations work.
Consider the tank probably holds more than 15 gals. so having 2 gals of lower octane fuel then diluted with 13 gals of the correct octane would hardly make a noticeable difference in the overall octane level in the tank. Not to worry, it won't harm the engine unless you do it repeatedly over the long haul.
Nope. Especially if you have some fuel in the tank. To be for sure for sure, you could put 2 gal of 93 octane in the tank.
Todays vehicles have sensors that will minimize harm due to pinging caused by low octane rated fuel in high octane rated vehicles. No it won't ruin anything.
As long as you put in quite a bit of 91, then it should be fine. It will overpower the 89.
Ruin? Not at all. Your Merc may be a bit teed off at you but other than that no harm done as long as you don't make a habit of it. Attentiveness will reduce worry in the future..
finish filling with 93 octane
It's not going to be a problem. It takes thousands of miles with the motor "pinging" to eat a hole in your pistons.
Fight fire with fire! Finish filling the fuel tank with 93 octane fuel.
You could add some octane booster.
On accident I pumped 2 gallons of octane 89 gas in my Mercedes which requires 91. I was just wondering if its going to do ruin anything?? Thanks
no.. LOL Just try not to ever do it again. It may effect the efficiency of it running tho.
Well you already drove home so it works fine....
now your warranty is void.
