You may have noticed that many new vehicles – most of them, actually – come standard with a turbocharged engine. It used to be generally true that only high-performance cars came with turbocharged engines.

There was a reason for that.

And it's reasonable to be leery about why that reason has changed.

Turbos used to be used to make an engine a high-performance engine; often, the engine was already a performance engine. The classic example is the Porsche 911's six cylinder "boxer" engine. It was already powerful – without the turbo. Adding the turbo made it even more powerful.

A turbo does this by using exhaust gas pressure (which spins a compressor) to pressurize the incoming air charge; instead of sucking it in – this is what naturally aspirated engines do – it is forced in. The additional air (and fuel) makes for a more powerful power stroke within the engine when the mixture is lit by the spark plug.

The end result is more power.

But also more pressure – on everything inside the engine. A more forceful explosion applies more force to the pistons and rings and then to the crankshaft and bearings – and so on. If the engine is small, it will typically have smaller surfaces to absorb all of this pressure, which concentrates the pressure.

The result – almost inevitably – is a shorter-lived engine.

Porsche 911 Turbos are fantastic cars but they are not generally cars that run reliably for 150,000-plus miles. That's the price you pay for driving a 911 Turbo. It's kind of like the price paid by body builders who take steroids