Last week, I decided to replace the ol’ spark plugs on my 2005 Subaru Impreza RS. While the car was running perfectly fine, I figured that they were due since the car had 105K miles on it. Luckily for me, yanking the spark plugs out of a non-turbo Subaru Impreza is completely drama free. Within a few minutes, all of the old ones were out and they clearly looked worn out. Their gaps were twice what the factory called for, and then some. It’s really amazing that the Subie wasn’t running rougher.
Before long the new spark plugs were tossed back in, and I was pleasantly surprised to find a noticeable difference in engine smoothness at idle, and while accelerating. I hadn’t realized that it wasn’t smooth before, until I felt the new smooth. Sure enough, the new smooth is considerably better. I’m hoping that this will gets me the other mile per gallon that I need to hit a consistent 30… We’ll see!