Not dead yet: The resilient ICE looks to 2050

The mobility industry will need to keep evolving the combustion engine for many years, says Dr. John Heywood.

April 1, 2018

Lindsay Brooke

For the sake of discussion, let’s say that 25% of the world’s light-vehicle production in 2030 will be battery-electrics. Such a prediction may seem quite optimistic, compared with most forecasts. But we’ll use it here. If 11 years from now a full one quarter of new vehicles roll off their assembly lines under electric power, the question then is:

What sort of propulsion will be powering the other 75% of new vehicles? And the likely answer will be, “Some form of advanced internal combustion engine; maybe a hybrid.”

It’s easy for some to overlook the reality of further ICE development when the EV-future story dominates the news. But truth is, the mobility industry needs the ICE and will continue to evolve it, as companies make their future-product bets for the next decade and beyond.

Dr. Heywood is the author of nearly 300 technical papers and five books. (Image: Lindsay Brooke)

That topic is the focus of an SAE Leadership Summit panel discussion titled, “Not Dead Yet—The Ever-Evolving ICE Powertrain,” at the WCX18. (April 12, from 9:00 to 10:20am at Detroit’s Cobo Center). Among the five panelists is Dr. John B. Heywood, one of the most highly regarded experts in ICE research. He’s the Professor of Mechanical Engineering and Sun Jae Professor, Emeritus, at the Massachusetts Institute of Technology and an SAE Fellow.

Dr. Heywood, whose many tech papers and books are well known (see sidebar), spoke with Automotive Engineering in late March, about the future of the ICE. A portion of our conversation appears below; the full interview is available on SAE.org.

How do you reply to those who ask, “Why is anyone still developing internal combustion engines?”

I get that question a lot. In the work my team did that was summarized in our report, “On the Road Towards 2050: Potential for Substantial Reductions in Light-Duty Vehicle Energy Use and Greenhouse Gas Emissions” [MIT Energy Initiative 2015], we found a useful unifying theme in looking at improvements to ICEs and what it would take to get to very large scale for the alternatives. The penetration rates of the various propulsion options are evidence why internal combustion dominates—because it best meets the needs of the market.

And even as those needs have evolved, the ICE still really meets them well. We simply cannot transform to electric propulsion that rapidly. The scale and thus the challenge are enormous. So, we’re going to need ever-better combustion engines.

On the freight side, the diesel engine is seriously under siege due to its air-pollution challenges. But we don’t yet have a replacement option. You can argue that battery-electric is a potential replacement for the gasoline engine. And while we don’t need the diesel in light-duty vehicles, we do need it in heavy-duty vehicles. That’s why we need much improved combustion engines.

Further work in diesel is mentioned in your new book. Do you see gasoline and diesel combustion systems ‘coming together’ more in the next decade?

There’s on-going work on using gasoline, or a fuel that’s like gasoline, in a diesel engine. Due to the importance of diesel for moving freight in the world economy, there might be a compelling reason on a large scale to really push using gasoline/petrol in modified diesel engines. Again, I think that will get into trial use as people explore its promise.

Cleaning up diesel in terms of air pollution is a big challenge. We’re going to have to make progress on that, because we don’t have alternatives that are convincing yet. I think we understand the complicated diesel combustion process better, so we’re at a good point to try to invent our way out of this problem.

You’ve been working on the interaction of engines and fuels. How can the industry optimize both?

The idea of engine-fuel interaction has really gotten traction. But the fuel industry is so vast, and is taking changes step by step. Scale is a very real constraint, and changes will be driven by economics and other practicalities. But I don’t think we’ve yet taken the opportunities that are starting to be identified seriously enough. These opportunities could lead to approaches like variable compression ratio.

An idea I, and others, are working on is an ‘octane on demand’ system. Here you blend fuel on the vehicle to deliver the octane that you need as the gasoline engine operates. You can do that with ethanol because it is a very high-quality fuel component. You can deal with the knock problem this way because most of time we’re driving we don’t need the high octane that we get out of the pump. It does require some changes that may seem a bit radical; they’re still in the development stage. We will need hardware that’s been tested extensively in real life, to sort out whether this really is a good idea. Matching fuels and engines is an area where we need to start investing and exploring.