Alternative Powertrains – Back to a Future of Many Choices

It was not that long ago that we grew up knowing only one type of automobile – one powered by an internal combustion engine (ICE). But that was not always the case. At the beginning of the 20th century, when electricity became widely available, there were nearly 34,000 electric cars registered on U.S. roads, accounting for nearly 40% of the vehicles on the road. Another 40% or so were steam powered, leaving ICE powered vehicles in the minority. For a period, New York City was dominated by electrically powered taxis. But, as oil-powered history took its course, ICEs grew dominant as the technology was perfected by the likes of Karl Benz and Henry Ford, giving us the mass produced automobile.

Can we call it “Back to the Future” when we look at what is happening today and where we are heading by 2050? As of 2016, there are already more than 75 models of alternative powertrain vehicles available for purchase in the U.S. market — plug in electric vehicles to hybrids and even fuel cell powered vehicles. At the turn of the 21st century there were still only two models – the Toyota Prius and the Honda Insight.

What has led to this proliferation? In part, it has been driven by the need for greater fuel efficiency worldwide, but also because of an emerging global awareness of the impacts of climate change brought about by carbon emissions. In fact, the U.S. 2025 CAFE standards that double the fuel economy targets are governed by the Clean Air Act and are designed foremost to lower greenhouse gas emissions.

Technological advances are a player as well – and that is across all powertrain technologies, beginning with traditional internal combustion engines. They are not going away anytime soon as they continue to grow increasingly more efficient and cleaner. ICE thermal efficiencies that were in the high teens are now approaching 40% in new designs from Toyota with the help of advanced designs. Highly efficient transmissions, stop/start systems and more efficient drivelines are further helping deliver more of the energy in the gas tank to the wheels.

Meanwhile, alternative powertrains are also on a fast track to improvement in performance and cost. Hybrids, and the more recent plug-in hybrids, have been around for nearly 20 years now. Toyota has perfected the science over four generations of the Prius, which is rated at 56mpg, combined EPA city/highway. The 2012 Prius already met the 2025 CAFÉ standard at the time the rule was signed nearly four years ago. Toyota alone has sold more than 8 million hybrids worldwide and there are some 60 hybrid models available from numerous OEMs in the U.S. today.

Today, much of the excitement surrounds electric vehicles whose powertrains are about four times more efficient than ICE powertrains at turning energy into motion. Now there are a dizzying number of choices that a typical consumer cannot even keep up with. Battery electrics are probably entering a “next-gen” era, and only after a very short 5-6 years since the “gen one” models hit the markets. What is behind that is the 65% reduction in automotive scale Li-ion battery costs in the last six years that are now making a post-government incentives price point of ~$30K for a car with 200 miles range on one charge possible. In this category, Tesla’s model 3 has garnered most of the press. But, it is often overlooked that GM’s Bolt meets those criteria and will be available later this year as a 2017 model. Of course sales of EVs are still in their infancy but their adoption rate has been much faster than that of hybrids and the new economics of the “next gen” models are likely to put their adoption on an exponential track.

And then there is what some have called the “holy grail” of propulsion technology when it comes to its cleanliness – the fuel cell. Promoters have been seen drinking the water that comes out the “exhaust” pipe of a fuel cell car to champion its virtues. Fuel cell technology has been around for a long time; but adapting to automotive use with its reliability/ durability requirements at a reasonable cost has proved elusive for many decades. However, Toyota’s Mirai, which is on sale in California and Japan, is one of the first to have a price tag that is within reach. And, in California the Mirai’s $60K price tag can be reduced by some 20% with federal and state incentives.

The advent of this new era of choices is great for SAE International because our Motor Vehicle Technical Standards Committee is busier than ever with new standards development. SAE’s Automotive Engineering magazine chronicles many of the new developments in each new issue. SAE’s professional development programs have added numerous new courses and the Engineering Meetings Board’s portfolio of conferences is shifting more and more to the new technologies. The Collegiate Design Series has added a Formula E and a Hybrid Competition.

Engineers are inherently at the core of early adopters of new technologies. But the average consumer is only just starting to appreciate the depth and breath of this new era of alternative powertrain choices that takes us “Back to the Future.”  By the time we hit 2050, within the career span of all the young engineers of today, none of this will be “new” anymore, but just the norm.