Originally Posted by millon9
Hard to explain exactly...but the engine seems more eager to start up, a little quieter at idle, and smoother idle and shifts. Not like it was knocking on 87, but it runs better overall.
I'm going to finish out my tank and pay closer attention to the sound. Mine has sounded more throaty since the fall and I just figured it was the factory exhaust having been broke-in. Sounds cool. At fill up, I'll try the 89 and listen and feel. Wouldn't hurt to try and check.