Shawn Kong

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?

RDOCA

No --the engine will pull timing and give you less power to keep from detonating but it wont hurt it.

Chigs

Drive very gently until you can fill it with 91.

Shawn Kong

I was just wondering is there huge differences between the 91 and 87 gas

boosteddub69

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.

8cd03gro

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.