Desperation brings out the worst in people – including engineers. But then, you can’t really fault them. The government issues its fatwas – which aren’t suggestions – and it is the job of the engineers to figure out ways to comply with the fatwas.
Hence, the becoming commonplace use of turbochargers and direct injection. Neither makes much sense except as measures to achieve compliance with federal fatwas, chiefly the one ululating that every new car must average at least 35.5 MPG and if not, its manufacturer will be caned in the public square.
Well, financially caned – via deliberately punitive “gas guzzler” taxes that are applied to the not-compliant cars. The taxes are passed directly to the buyer, who thus becomes less apt to buy – which renders it more difficult to justify making the car in the first place, particularly since its less-than-compliant MPG numbers weigh down the “fleet average” of the rest, risking more caning . . . er, fines.
So, turbos and direct injection.
Turbos used to be rare and used mainly to boost the power of diesel engines in heavy trucks and gas engines in high-performance cars. The additional parts could be justified because turbos were power adders, designed to make additional power in vehicles that were bought be people who wanted an extra dollop of horsepower.
Today, turbos are used to make up power lost to engine downsizing – which happened because of the first round of gas-mileage fatwas.
You may have noticed that as for instance V6 engines – which were once very common in mid-sized family cars – have been disappearing just as V8s – which used to be common in mid-sized family cars – also disappeared and for the same reason: Smaller engines use less fuel.
But it’s one thing to go down from a V8 to a V6 – and another to go down from a V6 to a four. Especially in a car that’s not larger than a compact-sized car.
Enter the turbo.
It boosts the output of what would otherwise be an underpowered engine that most buyers would find unacceptable. It brings the performance of a four up to the level of a V6.
It is basically compensatory technology. Uncle has decreed that you shall spend more for your next new car in order that it shall burn less gas.
How this is going to save you money is hard to divine.
Speaking of gas.
Direct gas injection (GDI) is another consequence of the fuel efficiency fatwas – and, like turbochargers – a compensatory technology. It increases both power output and mileage (about 5 percent, give or take) but not without cost – and other consequences.
In a GDI system, there is a hole bored into each cylinder, very much like a second spark plug hole. This is for the high-pressure direct injector. And it is very high pressure – operating at around 3,000 PSI.
Eric Peters [send him mail] is an automotive columnist and author of Automotive Atrocities and Road Hogs (2011). Visit his website
Copyright © 2017 Eric Peters
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