I've had no problems with my car and have even had my mechanic check it out within the last 6 months. A friend of mine recently told me that it was okay to use medium grade gasoline rather than premium unleaded (as it says by the gas gauge).

Could this be the cause for my check engine light? Using the lower grade gasoline?

Thanks.

 

I've been using regular for over a year with no problems. I don't think the grade of fuel could cause a 'check engine' light, unless you have a faulty, or overly sensitive knock sensor. You need to have the codes scanned - this will tell you what's causing the MIL light. Good luck.