The 6-cylinder engine is in decline. Fewer and fewer cars and SUVs are being outfitted with inline and V6s in response to tightening fuel economy regulations and cost savings. V8s are even rarer. Across the industry, these gas-loving engines are being replaced by turbocharged four cylinders that offer similar power and better fuel economy. But, for those who have been harangued by an 02’ Civic with a petulant exhaust, the word turbo may connote something obnoxious or inefficient. Let’s take a look at what a turbocharger is and why you shouldn’t worry if you’ve got one under the hood.
How Does an Engine Work?
Here is the simplest (the simplest!) explanation of what’s going on in your engine. In a standard engine, a combination of fuel and air go into the combustion chamber. A spark ignites the mixture and the explosion drives the piston down. The motion of the piston rotates the crankshaft and, for all intents and purposes, “drives” the engine. When the piston is pushed down, exhaust (a wasted byproduct of combustion) is also released from the engine. The piston rises again and the process repeats. But turbocharged engines do not waste the exhaust.
What Is a Turbocharger?
Instead, the released fumes spin a turbochargers turbine as they leave the combustion chamber. The turbine forces the induction of more air into the combustion chamber allowing the allowing the engine to generate more power with less fuel. A turbocharger is a really simple machine, when you think about it. But how effective is it?
Adding a turbocharger to a traditional engine improves its fuel economy by roughly 2 to 6%. That sounds insignificant, but only because we’re now comparing two engines with different amounts of power. It makes more sense to compare a smaller turbo engine to a larger, naturally aspirated engine that generates the same power.
So, if you consider that a turbo four is replacing a traditional V6, the fuel savings are greater. Four cylinder engines are lighter and smaller than their six cylinder counterparts, making the vehicle more fuel efficient overall. This is the main reason we’re seeing turbo fours in the majority of passenger vehicles.
In the public discourse, turbochargers are associated with short engine life and engine failure. Why? If you take fewer cylinders and force them to complete more combustion cycles they won’t last as long. But this was mostly a problem for engines with aftermarket turbochargers. Considering most manufacturers have common sense, they only pair turbochargers with engines built to withstand extra force. That means lots of high-strength steel.
Another problem of older and aftermarket turbos is cooldown. Turbochargers can spin up to 150,000 rpm and they get extremely hot! If you drive your turbo hard and then shut it off immediately, oil would coke and ruin your turbocharger. But modern engines feature water cooling and cool much more effectively so you usually don’t have to worry about things like idling your vehicle before your shut it off.
Ultimately, the turbocharger is a useful innovation for getting more power and using less fuel. They’re no longer just for modified Civics with race decals, and they won’t destroy your engine.