Saab offered water injection for the Saab 99 Turbo. With the introduction of the intercooler the interest in water injection to prevent detonation almost disappeared, but recently water injection has also been of interest because it can potentially decrease nitrogen oxide (NO) and carbon monoxide (CO) emissions in exhaust. However the most common use of water injection today is in vehicles with high performance aftermarket forced induction systems (such as turbochargers or superchargers); such engines are commonly tuned with a narrower margin of safety from detonation and hence benefit greatly from the cooling effects of vaporized water.