Filling your front tires with 40 to 50 pounds of air will make them roll easier, but it works best on a racecar. On a street car that is driven a lot, and in pretty rough terrain (potholes and the like), you’ll eat up the center of the tires faster than the outsides. The turning grip will be impaired, and it will make for a rougher riding car. Thus, you make the call as to what is appropriate for you at the strip or on the street, but be sensible. It is free horsepower due to lower rolling resistance, and that’s key—unless you have a canyon carver. Then the tradeoff becomes more rubber on the pavement. Also, if you run slicks on the strip, or soft-compound tires designed for better traction, they should be filled up with as much air as possible before they break loose. So you will have to fiddle with air pressure to get what works best for your car (and more than one air pressure setting if you have a dual-purpose car). Remember that slicks with too little air in them can make the car very unstable, especially at speed, and it doesn’t make the car bite any better anyway. While tuning at the strip, try starting at around 15 pounds, and test it up and down in 1- or 2-pound increments to see what works best on your car. But bring the tire pressure back up to normal street-operating pressure before hitting the streets. Many guys will use two different sets of tires for this purpose, so work that out too, as you progress. There’s a lot here for those who wish to spend the time learning.