You’re considering installing a cold air intake system and you’re wondering exactly 'how much horsepower does a cold air intake add?'. Exactly how much of an increase in horsepower and torque you will receive will vary depending on what kind of car the system is installed in and exactly which system you use. On the average, you will see between 8 and 25 more horsepower when you install one of these on a properly tuned engine. The power gain is realized because cold air is denser, with a higher percentage of oxygen than warm air. More oxygen, means more power.