Hi,
I have been changing my gas from regular unleaded (87 octane) to special to sometimes premium. Will there be any affect on my car due to this? I have noticed that changing to a higher grade made the car go more smoothly(maybe I am hallucinating).? And will there be any gas mileage increase because of that? I thought I noticed some change.
But the bottomline is , MUST I use for the grade (87 octane) or can I change the grade as I please?
Thank you. Rahul