Saturn S series Twin Cam cylinder head had now featured a new roller-rocker setup with hydraulic tappets and roller cams replacing the conventional bucket lifter setup of the previous engine in the S series. Also introduced for the 1999 model year S-series vehicles that were sold in California was a different type of an exhaust manifold that housed an upstream catalytic converter (this converter had heated up much faster than the conventional unit, and it had also decreased exhaust emissions faster as well), and it also had provisions for an air-injection reaction system (This had injected fresh air into the exhaust to reduce
Steam car A significant benefit of the ECE is that the fuel burner can be configured for very low emissions of carbon monoxide, nitrogen oxides and unburned carbon in the exhaust, thus avoiding pollution. The greatest technical challenges to the steam car have focused on its boiler. This represents much of the total mass of the vehicle, making the car heavy (an internal combustion-engined car requires no boiler), and requires careful attention from the driver, although even the cars of 1900 had considerable automation to manage this. The single largest restriction is the need to supply feedwater to the boiler. This must