A turbocharger is an air compressor which sucks air in and squishes it up. This compressed air will carry more oxygen so you would be able to burn more fuel.

The fuel and air mixture in an engine is vital and you can only run an engine when this ratio is correct.

Early pilots, especially in wartime needed more altitude and more speed. The issue was that the higher you went the slower the engine ran, and if you went too high the engine would stall completely. Early aeroplane engines were fuelled by petrol or ethanol and have a lot in common with the modern automotive engine. With aeroplane engines the problem was getting enough air into them at high altitude where the air is thinner and contains less oxygen. A way to compress the air was conceived. source on turbo history

The turbo has two turbines connected by a spindle. On one site it is spun by the flow of exhaust gases and this in turn rotates the other side, the compression part. This enables an engine to produce far more power and work in extreme environments.

Modern sports cars greatly benefit from the addition of a turbocharger, take the impressive Porsche 911 as an example. Without a turbo it was just a run of the mill sportscar but the turbo has taken it into the supercar league.

The turbo does require an engine to be producing enough of an exhaust gas flow before it can work. This phenomena is referred to as turbo lag. In a car engine you will reach a point in the RPM range where you suddenly feel the turbo cutting in and boosting the engine.

Large turbos produce more power but require more exhaust gasses to flow so are more laggy. Small turbos spool up more quickly but run out of boost quite early on in comparison to the large turbos.

Some manufacturers have pioneered variable vane turbo geometry to reduce this risk. At a set point in the rev range the geometry changes to lengthen the boost range and get the turbo to cut in earlier.

The diesel engine has been revolutionised with the advent of the turbo and we are seeing turbo technology coming over to petrol engines now. It is impressive to see a small 1400cc engine producing as much power as a traditional 2500cc engine. It is lighter so the car feels quicker, it will also be cheaper to run and parts costs less on smaller engines so it is a win all round.

So we can thank the early pioneers of flight for introducing the innovation of the turbo to our cars and helping us to drive more efficient and more powerful engines.