If you use a lower than recommended level, the gas may combust too fast for your engine.
Get Do Bmws Use Premium Gas
Gif. Here is my take on it: Don't use regular gasoline in your bmw if it falls in one of the following categories
Is Premium Gas Worth It We Test High Octane On 4 Popular Vehicles from hips.hearstapps.com
Is premium gas worth the premium price? Here is my take on it: Is it really necessary to use premium on a 4cyl?
If not, any of the higher tier gas brands that have 93 works just fine for me.
In a nutshell, buy the gasoline your owner's manual calls for. Bmw vehicles use premium gas only. Look at it this way, the price diff is what 1.50 maybe 2.00 per tankful. They said that the computer would compensate for the lower octane by changing the timing and it is a waste of money.
