Both are practically the same thing and only serve to advance the time, and cause your car to run rich, basically it's a resistor that fools your car into thinking that the air that is entering the engine is cooler than it is, thus adding more fuel. However, the air isn't cooler, so the added fuel just makes you run rich which can be dangerous to the engine if it goes on for a long time
and after awhile...the computer will figure it out...so it will just run back to normal after awhile...i guy i know here in town ran one...it was good for like and hour...and then the car compensated for it. he could have made himself one and saved his money
