I took my 2002 C230K-auto to have these warnings checked out and to see if the could determine the cause of a hesitation from a stop. I also mentioned that the car had a hard time starting after it sat out in 30 degree weather last weekend. It sputtered and sounded like it was firing on 1 or 2 cylinders. The second attempt at starting it fired just fine. The service writer said I should use 89 rather than 91 octane and this starting problem would go away. The car hhas 1600 miles on it and no modifications. Is he correct?

 

the reduction in octain is a fix /bandaid for some running conditions.
i would try it .only for colder months,,then go back to 91 for summer