When it comes to modern engines, there are many flavors of high-performance. Turbocharged engines are a popular option; but in his most recent episode of Engineering Explained, Jason Fenske takes a look at five reasons he thinks naturally aspirated engines are a better choice.
The reasons Fenske gives can be boiled down to this shortlist—throttle response, torque curve, reliability versus cost, fuel efficiency, and sound. This really stuck out to a few of us on the Hagerty team, because nothing from this list truly applies to modern engines like the Ford Ecoboost or Subaru EJ series. If this list was based on 20–30-year-old technology, most of these points would hold up. However, turbo technology has come a long way in the last decade or so.
For instance, throttle response on newer turbocharged engines is not nearly as lagging as Fenske describes. With twin-scroll turbochargers and relatively powerful base engines—meaning engines not completely reliant on the turbo’s boost to make respectable power—tipping in the accelerator pedal gives many cars a meaningful thrust forward. Fenske seems to be comparing the race-bred Lexus V-8 he is driving in the video to an economy car with a turbo for better fuel economy—a fallacy he is typically above.
A few of the other points are purely subjective, such as sound. Yes, we have to agree that a high-revving N/A engine often sounds fantastic. However, the sound of a big single turbo coming onto boost right as forward thrust forces your grey matter against your brain stem is intoxicating. Different strokes for different folks, and the muffler effect of a turbine wheel in the exhaust is hardly a legitimate reason to reconsider purchasing a turbocharged engine. Plenty of folks think 911 Turbos sound great.
He does have one pretty solid point buried in here though, and it’s about turbo cooling and oil life. Decades ago, turbos were mainly cooled by oil only. This could lead to coking—which can loosely be thought of as “boiling the oil”—and leaves deposits and restricts future oil flow. Poor oil quality or flow leads to damage to the turbine shaft bearings—something costly to repair. Modern turbos are cooled by both oil and water now though, which prevents many of the issues which plagues the turbines of yesteryear.
All of this is to say: there are more than five quick things to consider if you’re looking to purchase a turbocharged engine. Use case and the engine’s suitability for that intended use should be two of your main concerns; but rarely do things in the automotive word condense into lists of five.
Sound off in the Hagerty Forums below with what you look for in an engine. It might help someone else decide just what will be the next addition to their garage.