One main advantage of pre-cooling is (as predicted by the ideal gas law) for a given overall pressure ratio, there is a significant reduction in compressor delivery temperature (T3), which delays reaching the T3 limit to a higher Mach number. Consequently, sea-level conditions (corrected flow) can be maintained after the pre-cooler over a very wide range of flight speeds, thus maximizing net thrust even at high speeds. The compressor and ducting after the inlet is subject to much lower and more consistent temperatures, and hence may be made of light alloys. This reduces the weight of the engine, which further improves the thrust/weight ratio.