Using a hot plug can cause the engine to be a real challenge to tune. I live in Miami and it gets damn hot during the summer, it forces me to run a cold plug. Im gonna try getting a medium plug because with the cold plug for the first couple mins of drving it doesnt run right, then when the engine heats up its fine, but with a hot plug its impossible to get the tuning right. i think the Med plug will be the perfect middle ground.