i think there's a few:
1. keep too much heat from getting to the hood and possibly affecting the paint(this is said to be a rumor)
2. in cold weather it prevents the engine from cooling too fast and causing cracks in the engine block and heads
3. smothers engine in case of fire
1. keep too much heat from getting to the hood and possibly affecting the paint(this is said to be a rumor)
2. in cold weather it prevents the engine from cooling too fast and causing cracks in the engine block and heads
3. smothers engine in case of fire