The On-Going Relevance of the Internal Combustion Engine

One day the world’s roads may be filled with vehicles that emit just a hum from their motors. But in the meantime, there are all of those vehicles being built with engines that have exhausts that need to have their emissions minimized and their sounds optimized. Which is what Tenneco’s Ben Patel is focusing on.

Although there seems to be a cacophony of voices in the industry talking about the Electric Automotive Future, all sounding like the Fuel of Tomorrow is going to be coming out of a plug rather than a nozzle, Ben Patel, vice president and chief technology officer of Tenneco (, doesn’t see it that way. “Our thesis is that for a long time the internal combustion engine is going to be viable, even with the expansion of electrification.” Note well the electrification. He says that for “the foreseeable future” they anticipate hybrids will be the dominant form of vehicles with additional electrification, which means, of course, that the internal combustion engine continues to be part of the propulsion system. “Electrification, when you peel back the onion, is really about hybridization, 48-volt or plug-in,” Patel says, pointing out that the pure battery electric vehicle will not be the volume play for some time to come. “Even if it’s a range extender”—vehicles like the Chevy Volt and the Karma Revaro (yes, it has dual electric motors that produce 403-hp and even photovoltaic cells on its roof that provide an output of 200 W, but it also has a 235-hp 2.0-liter turbocharged four functioning as a generator for the electric batteries)—“it has to be tailpipe-compliant.”

Tenneco, a $9.3-billion company with a global footprint, develops and produces a number of components and systems for handling vehicular exhaust, light-duty and heavy-duty, gasoline and diesel. (It also produces products like shocks.)

In April 2018 Tenneco announced that it signed an agreement for the $5.4-billion acquisition of Federal-Mogul, which, like Tenneco, has a focus on the engine (as well as, like Tenneco, has an aftermarket business). Patel points out that whereas Tenneco’s historical real estate on the vehicle has extended from the exhaust manifold to the tailpipe, with the Federal-Mogul acquisition, which brings components including pistons, liners, rings, and bearings, “Now we’ll start in the cylinder.”

(The plans call for Tenneco to operate two companies, one the Powertrain Technology Company, which combines Tenneco Clean Air with Federal-Mogul Powertrain; the other the Aftermarket and Ride Performance Company, which combines the Tenneco Ride Performance and Federal-Mogul Motorparts OEM and aftermarket businesses.)

Of the company’s approach, Patel says, “We’re doubling down on the internal combustion engine.”

However, as OEMs focus more on things like electric—and autonomous—vehicles, their engineering teams—and their budgets—are being focused away from some of the traditional areas, even though they are still faced with things like regulatory requirements that are dictating what can, and cannot, be emitted from the tailpipe. This, Patel suggests, is one reason why there is a need for suppliers that can provide entire systems rather than just components (“If you want to buy components, we’re happy to sell them to you, but we would prefer to start the conversation much higher up, at the systems level,” he says), systems that can consist of standard modules so that there can be cost-effective application across a number of vehicles.

For example, he cites a full exhaust aftertreatment system. It starts at the exhaust manifold with close-coupled converters to maintain the temperature coming off the engine for things like light-off, an integrated exhaust gas heat recovery unit that deploys a heat exchanger with coolant and a bypass valve so some heat energy that is ordinarily lost as exhaust gas can be recovered (which is particularly useful for hybrids, for things like meeting defrosting requirements and heating the cabin quickly after start-up), and, instead of a custom muffler box for every platform, a standard unit for sound attenuation that’s tuned with software and uses a speaker system to fine-tune the exhaust note with a standard design. Patel suggests that this systems approach is beneficial so that there doesn’t need to be engineering and reengineering multiple times.

Speaking to one of the elements alone—and know that this is an approach that relates to other elements, although not necessarily in the same way—he says, “If we can shrink the muffler box by 30 percent, there’s no reason why not to use it everywhere.”

Although there is presently flux vis-à-vis emissions regulations in the U.S., in other parts of the world requirements are stringent and getting more so. Patel references Euro 6, India’s Bharat 6 and China 6. As a global supplier, Tenneco must be capable of dealing with vehicle manufacturers’ needs wherever.

However, while they’re looking for modularity and redeployability, Patel points out that there isn’t a one-approach-fits-all situation. “Even though technical requirements may be the same”—as in dealing with what comes out of a tailpipe—“the market is different.

“Volvo Eicher in India doesn’t want the Volvo European solution even though Bharat 6 is like Euro 6. They know they can’t afford it.”

So Patel says they have to do things like finding less expensive materials and use thinner gages. “We must maintain the functional performance while being able to offer the design at a lower cost.”

Or in China, the heavy-duty truck situation is different than in the U.S., as due to the way trucks are acquired and used, they don’t have the same sort of expected longevity as is the case in the U.S.: “You don’t design for one-million miles of useful life.” Again the challenge: “How do we take cost out without reducing performance?”

And when the overall topic is the heavy-duty truck, it comes around to diesel, where Tenneco has done considerable work. While Patel acknowledges that when it comes to light-duty applications, which are primarily European autos, the market is shrinking, but that doesn’t have much of an effect on Tenneco, as for light-duty diesels it primarily supplied components to the cold end of the exhaust system. He expects diesels will continue to be the dominant type of engine in commercial vehicles going forward. This means that they’ll need full aftertreatment systems.

In the U.S., he says that the current NOx standard for heavy-duty trucks went into full effect in 2010: 0.2 g/bhp-hr. The California Air Resources Board (CARB) has been looking at the way this can be cost-effectively reduced by 90 percent to 0.02 g/bhp-hr. CARB contracted with the Southwest Research Institute ( on an active demonstration program of which Tenneco was a part. Patel says that the reduction can be made—cost effectively.

Whether the engine uses spark ignition or compression ignition, there are things from sound to criteria emissions. Which is what Tenneco has been addressing historically, and which it will address more comprehensively with the addition of Federal-Mogul’s engine expertise.

As someone who is involved in research and development, Ben Patel knows that the large global OEMs are directing much of their resources in things ranging from artificial intelligence to mobility services. But he points out, “In the meantime, we all have to build conventional automobiles. We can’t forget about running the business.”