My wife's car (a Ford) was rear-ended a couple of weeks ago, and since then, we have been using the MB exclusively. Some of our driving has involved a 100-mile or so trip once a week at high speed. We had been making the trip with the Ford, but now we do so with the MB ('84 380SE). I also am filling up with Chevron 91-octane. The result: The first week, I noticed that the MB's behavior was improving. After the second week ... well, she knocked my socks off. She's never been better! It's truly amazing what happens when you drive these cars as intended!