To Blow or Not to Blow: Turbocharging vs. Natural Aspiration

From the June 2016 issue

Every new BMW on sale in the United States, save for the electric-drive i3, carries at least one turbocharger. Audi and Mercedes-Benz are nearly as turbo-centric. Even stalwarts of high-revving, naturally aspirated engines, such as Ferrari and Honda, are strapping snails to their engines. And on the home front, Ford has been pushing hard on its EcoBoost turbocharged engines for almost a decade now.

If turbochargers haven’t won the war against natural aspiration yet, they certainly appear unstoppable in this, their most recent campaign for domination. Increasingly stringent fuel-economy and emissions regulations worldwide are driving this switch to forced induction because turbochargers allow carmakers to maintain performance levels while reducing engine displacement and improving EPA fuel economy. Honeywell, a leading turbo supplier, reckons that by the year 2020, 39 percent of all vehicles sold in North America will have turbos, up from 23 percent in 2015.

Turbocharging’s day has been long in coming, considering that the concept has been around for more than a century. It’s been 54 years since General Motors fitted turbochargers to the Chevy Corvair Monza and the Oldsmobile F-85 Jetfire, and more than 40 since the Porsche 917/30, turbocharged to 1500 horsepower, laid waste to Can-Am competitors.

But turbochargers aren’t just for performance cars anymore. They are now the solution of choice for all segments of the market, from city cars to luxury cruisers to—thanks to Ford—full-size pickup trucks. Once you lose V-8–loving truckers to a turbo V-6, the war is all but over and it’s just a matter of signing the surrender documents.

On the following pages, you’ll find four head-to-head matchups of turbocharged vehicles and their naturally aspirated competitors, covering the breadth of the light-vehicle market. Beware: These are not conventional comparison tests. We’re focusing these stories on the characteristics of the engines and judging the suitability of engine type for each class of vehicle. We also strapped our test gear to several cars to answer the two main questions at the heart of the turbocharged revolution: Do they really save gas, and has turbo lag truly been vanquished from forced-induction engines?

Let the spooling begin.