Bad fuel?

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Site Donor 2023
Apr 4, 2012
Kendall, FL
Been using 87 octane from various stations with the Sonata. Last week i filled the tank with 16 gallons (full tank is 18.4). I didn't notice immediately because of the radio but the following day i could hear a faint ping on acceleration. This began to worry me of course but before going to the dealer, I decided to use up this tank-full and fill up somewhere else. I did so at another major chain and thankfully, the ping completely went away.

Q. What, in the old gas, would cause the engine to ping?
This happened to my old cruze, along with poor acceleration. Went away after I filled up next time. I would recommend avoiding that station. It seems the Oceanic near me is notorious for bad gas.
Originally Posted By: Quattro Pete
Stale/old gas will have a lower octane rating.

Originally Posted By: Donald
What about the anti-knock sensor? It should adjust to prevent the ping/knock before you can hear it.

The anti knock/timing feedback loop can only retard timing so far. That must have been really bad gas.
It was very faint and possibly wouldn't be noticed by most. But the higher OCD sensitivity towards anything vehicle related by a bitoger made me very aware it was there. I will monitor but thankfully it's gone. And by gone I mean, there when I rolled into the gas station and gone when I left. The station where I filled up prior was a Truck Stop Shell next to the Everglades. The second station was also a Shell. Both have a lot of use.
"diesel in fuel"

Had that happen one time. Terrible gas. A fellow who worked in the station told me that one truckdriver didn't fully drain the diesel fuel before he took on his load of gasoline for that delivery.
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