I am a recent owner of a 2002 C240. I have to say that I love it. there is nothing like driving a Mercedes Benz. I do have 1 complaint. My car burns gas like you would not believe. I read through the manual and it says ONLY use 93 Octane Gas(the good stuff). No problem, but when I use the high stuff, I find myself filling up 3 days later. Would it really hurt my car if I used the "middle" grade gas? Where I live the average price for 93 is $2.28/gal. The middle grade is averaging $2.09/gal.
Will the middle grade hurt my car? Is it some Mercedes Benz law that states that you can only use 93 octane in your car?

SOMEONE PLEASE GIVE ME SOME INSIGHT.

Signed,
I'm off to the gas station again