From what I've read, using regular in a car that calls for premium won't harm the engine the way it did years ago--the onboard computer will automatically adjust ignition timing to compensate for lower octane rating and prevent knocking. But the car's performance won't be what it would be on premium. There's no benefit to putting premium in a car that calls for regular.
There's a big difference in the way it runs between regular and premium, I hit the wrong button once.
I decided to look at a mercedes-benz forum for input from other people with a mercedes-benz. Some say there's a difference, others can't tell.
Someone also mention that Premium works better on hills. Valparaiso has its ups and downs!
I've also read that the engine will adjust for the knocking but premium burns cleaner and over time this becomes a problem.
Long as I remember The rain been coming down. Clouds of Mystery pouring Confusion on the ground. Good men through the ages, Trying to find the sun; And I wonder, Still I wonder, Who'll stop the rain.
