Have your son sit in the passenger seat with the laptop hooked up while you drive the car down the freeway. He'll be able to change the ignition timing and the air fuel ratio while you're driving. You can just keep leaning it out until it complains and then richen it back up a bit. He can watch and see how much fuel it is using as you drive. It is the best way to tune a car that I know of since you can tune it while you drive and immediately feel the difference. Once you've done that a few times you'll really understand the tune.