I selected the wrong grade of gas, but then I quickly pushed the correct button on the pump. Does it change after it starts?

  • You can tell what grade you selected by the price you were charged. – cory Nov 9 '16 at 14:58

If the pump changed the fuel grade it was pumping you'd see it in the price. My gut sense is that it won't change – too unusual a use case and too much cause for confusion.

That said, don't worry about it. If you put in a higher grade than you need, that shouldn't be a problem at all. If you put in a lower grade then you might notice some pinging and it would be a good idea to fill up with the proper grade as soon as you can.

  • That and the likelihood that you had a totally dry tank is next to zero so there was some of the old gas mixing with the new so it isn't like you had only new gas. Just top off sooner to keep mixing the gas and pushing the mix towards what you wanted. Unless you chose diesel instead of gas in which case go to your mechanic soon. – Blackbeagle Nov 11 '16 at 2:12
  • I'd say 99% of cars on the road these days won't care what grade you use, they'll all have knock sensors and will work it out. – John U Nov 11 '16 at 15:45

No, not where I live. The other selections are not available after choosing one and the pump will not change while you are pumping.

To change, you would have to complete the current transaction, then start a new one with the grade selection you originally intended.

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