My 2002 C230K, auto, 1800 miles is hard to start in weather under 40F. It sputters, coughs and sounds like it is running on 1 or 2 cylinders. I shut it off, and it restarts fine. The dealership told me to use 89 octane gas in colder weather to cure this problem. This contradicts everything in the owners manual and every other piece of paper I received with the car about never using anything less than 91 octane. Any comments? Thanks.