87 regular gas VS 91 Premium Gas
#2
MBWorld Fanatic!
#5
Member
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.
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.
#6
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.