The last few drives in my wife's 2003 C320 I noticed it was running rough.


I picked up a big bottle of Lucas fuel treatment and filled up the car with Super.
She told me not to put super because it cost more.
I found out she has been putting regular gas in the car for a year.


I fussed at her and blamed the cars condition on low octane fuel.
We ran out the interstate for 40 miles and back at about 75. When we got back it seemed to idle better, but it seems to want to stall at take off.


Any ideas