Hey guys. The other day, on my way to school, I noticed that my car was running very slow. I would floor it (not hitting the switch) and the car wouldn't pull out of the 2-3k rpm range. I was rather alarmed but because I had school, I just parked the car and went on with my day. On the way back, the car wasn't nearly as slow as it was in the morning, but it was still slower than usual. This has been going on for the past couple of days. I timed my car today, and its running 0-60 in the high 9s. About a second slower than the mercedes specs... It doesn't seem nearly as responsive as before, and im having to hit the floor switch in order to maintain speed up hills. This slowness has coincided with some cold weather around here (Austin) In the mornings its around 32, and by the time I get home its around 55. I had 10w40 oil put in my car a few weeks ago. (Somebody had suggested 15w40, but the guys at jiffylube, my dad had it changed, said that it was used for diesels) Does anyone know what the problem might be? I have never driven the car with this oil cold before, could it be the oil? Even when the engine/oil warms up (15+miles), the car is as sluggish as when cold. Any suggestions would be greatly appreciated.