[Kennection]

Ok so I remember hearing about how the 318ti's don't use regular gas, and use the 92(I believe it's this one?). So yea, my very first car as a 17 year old, so I'm not all knowledgeable with my car yet (Parents bought it from a friend for me). Anyways, my grandfather has a spare key to my car, and when he notices that I'm almost out of gas, he'll go out and fill it for me. I just found out that the past two times he's been filling up the car, he's been filling it up with regular gas.

My question is, should I be noticing something about my car when it's been filled up with regular gas?

I was driving it around today, to do some errands and I started noticing how my car was making some really odd noises. I would step on the accelerator and would notice some noises coming from the engine for about a few seconds, then it'd go back to regular. Also would notice that when I let go of the accelerator and was about to tap the brakes.

Not sure if I should really be worried or anything, or that I should just wait for my gas to run out after awhile and fill it up with the premium gas.

Thanks.