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87 regular gas VS 91 Premium Gas

 
Old 02-05-2019, 07:37 PM
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87 regular gas VS 91 Premium Gas

I just picked up the new vehicle but my wife accidentally filled up the 87 regular gas. Does it hurt my C43 V6 engine?

Any thought?
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Old 02-05-2019, 08:31 PM
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Originally Posted by Shawn Kong View Post
I just picked up the new vehicle but my wife accidentally filled up the 87 regular gas. Does it hurt my C43 V6 engine?

Any thought?
No --the engine will pull timing and give you less power to keep from detonating but it wont hurt it.
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Old 02-08-2019, 02:07 PM
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Drive very gently until you can fill it with 91.
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Old 02-13-2019, 09:35 PM
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I was just wondering is there huge differences between the 91 and 87 gas
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Old 02-14-2019, 09:01 AM
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Pretty good and concise article that should answer your question:
https://www.fueleconomy.gov/feg/octane.shtml
In a nutshell...don't try to save a few bucks by putting 87 octane in a C43 and if you do it accidentally it won't destroy your engine.
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Old 02-14-2019, 06:41 PM
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The difference is reactive in nature. 87 octane has less resistance to knock. When the ECU sense knock, it will pull timing until knock feedback is within the acceptable range, then it will attempt to creep back up to the default timing advance until it senses knock and pulls back again. Will it damage anything in one instance? Very unlikely. You should try to fill it up with premium every time though. You could also add premium to the tank as you burn through the 87 to bring up the average octane. It's not the end of the world though.
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