Modern fuel-injected and turbocharged technology prevalent in vehicles today means that extracting more power has become easier. Strapped to a rolling chassis dynamometer (dyno, in the colloquial), a competent tuner can extract more power, torque, efficiency and responsiveness while measuring the actual gains consistently and repeatedly. Tuning is, after all, science and not magic.
The problem with traditional tuning is that you need access to a tuner who owns the requisite tuning software for your vehicle to reflash the engine control unit—or reprogram the engine parameters—or a stand-alone ECU….