Two-stage compression is 8-12% more efficient than single stage compression.GARDNER DENVER's new two-stage VST Series is a more efficient air compressor than other single and two-stage compressors on the market today. The VST Series compressor matches the compressor output (Supply Side) to the system requirements (Demand Side) at the target pressure required by you the customer. The GARDNER DENVER VST out performs other base load and other variable speed compressors. With the variability found in most plant air systems and the ever-escalating cost of energy today, the VST product is the smarter solution. The VST offers a reliable and stable air supply at the least energy cost.