[Ken07335i]

My sig is an older car. I've got an 2013 335i 6m E93. It says min 89 octane on the filler door, so I filled it with BP 89 to test it out. No knock and engine seems fine. I've just filled it again this time using Sunoco 89, and same thing - no knocking and seems to be running fine. Am I damaging my engine or not? Thanks.

[Welcome to NBA Jam]

No you're not doing any damage.

[floydarogers]

Originally Posted by Ken07335i

My sig is an older car. I've got an 2013 335i 6m E93. It says min 89 octane on the filler door, so I filled it with BP 89 to test it out. No knock and engine seems fine. I've just filled it again this time using Sunoco 89, and same thing - no knocking and seems to be running fine. Am I damaging my engine or not? Thanks.

This has been answered hundreds of times, in dozens of threads. Please use Search function.

No, you're not.

[fredcase]

Its likley pulling timing.

[6ixSpd]

Yes you should only be using 104 Octane with octane booster on newer F series cars.

[hassmaschine]

Less power, but no damage. The engine is programmed to work with a wide variety of fuel grades, even 87 octane, as BMW markets to soccer moms and non car enthusiast types they know damn well are going to put in the cheapest piss gas they can find.