First tank of gas:the first spark knock occured as I was accelerating onto an on ramp for the highway, car had less than 100 miles on it. I backed out and reapplied on the gas pedal. This did occur a second time on another date. I figured the gas was the reason so made sure to keep filling up the gas tank with the highest octane I could find. I have not gotten the spark knock since but the car is severely underpowered while cruising and then have to slow down for traffic. I will seperately list this problem when the car jerks after trying to accelerate.