SAE WCX 2022: Driveline Flexibility Is Key for Electrification

An expert panel discusses the future of axles, transmissions and drivelines as vehicles become electrified.

Industry forecasts predict that by 2030, non-electrified powertrains will be surpassed by electrified options. (FEV)

The electrification of light-vehicle powertrains is now not just probable, it is inevitable. OEMs and suppliers around the world are looking at all possible means to reduce the CO2 footprint of their vehicles while also meeting ever increasing fuel economy standards. IHS Markit is currently forecasting that by 2030, non-electrified powertrains will be surpassed by BEV, PHEVs, and other electrified options will make up over 50% of the market in light vehicle sales. IHS is also predicting that BEVs will overtake ICE within this timeframe and that ICE hybrids/BEVS will each make up about a third of the market by 2031.

This seismic shift in powertrain technology and development was discussed at length during SAE’s 2022 WCX panel “Drivelines and Transmissions: Balancing Today’s Solutions with Tomorrow’s Technology.” The panel was moderated by SAE Media editor Lindsay Brooke. “It’s important to remember that even under this forecast, ICEs will still account for a third of the market on their own, which is still a very large number,” Brooke noted to the audience.

The panel included (above, second from left) Kiran Govindswamy, senior VP of FEV North America; Gunther Rabb, VP of Engineering at BorgWarner PowerDrive systems; Mike Solt, Global Head of Transmission, Driveline and Axles at Stellantis; and Craig Renneker, VP of Product Engineering and Drivelines at American Axle & Manufacturing. The following are some highlights from the 90-minute discission.

What is the future of conventional automatic transmissions, axles, transfer cases, and other components with the widespread electrification of powertrains?

Solt: “To be honest, nobody knows. So, we’re going to position ourselves to be ourselves so that we can go right, left, or down the middle. But we’re still launching new transmissions. We’re not necessarily doing clean sheet designs, but we’ve got some new (transmissions) coming out. The majority of them are hybridized, but we still see that as a middle ground that will be there until it doesn’t need to be. I realize BEVs are accelerating right now like crazy, but I think it’s going to be an S-curve. Getting the last 20-30 percent of folks into a BEV is going to require something pretty unique.”

Renneker: “As Mike said, we don’t really know yet how much of the world can be covered by a battery. I was pretty skeptical that it would be a significant number a few years ago. In fact, if you had gone to a transmission conferences five to six years ago, we would always get this question: ‘When would BEVs hit five-percent of the market?’ The answer was always ‘maybe 2040 they may be five percent of the market.’ That has changed so radically in the last few years. And I think it’s because of this acceptance and realization that BEV is not what we thought it was going to be. It’s not a Leaf, it’s a Model 3, it’s an electrified Wrangler. It’s a vehicle that can have amazing performance. So, it will cover a much larger percentage of the market but as we’ve said, it won’t be all of it. The good news from our perspective is they (EVs) scale quite easily. It’s actually amazing how well electrified drivelines scale from a B car to a Ford Super Duty versus an ICE where every single part has to be re-engineered.”

Rabb: “Looking at the global market not every place will be able to build the same infrastructure at the same speed. So, I believe there is still a market for both conventional and electrified powertrains. Electrification is certainly the big trend both for hybridization and fully electric vehicles. But overall, the question for me is how much more innovation is still to go in conventional powertrains? We (currently) have good technologies that are very well-developed in that sector. So, I believe what will happen is the speed of innovation in that sector will slow and begin to pivot towards electric powertrains.”

Has the regulatory landscape finally stabilized to the point where OEMs and suppliers can plan more accurately than you’ve been able to in the past?

Solt: “I’ll give you a straight answer to that question:No. Can any of us really predict what we think the regulations are going to be in five years when we went from one administration changing the standards down only to be completely overturned by another? So no, I think the instability is growing. My team has to go put a plan together for the new CAFE standards that didn’t exist a few months ago which is going to have massive implications for everyone’s plans. I think the volatility is unfortunately only getting worse. I’m very interested to see how the OEs are going to attack all these new U.S. regulations.

Some OEMs have gone to modular or “one size fits all” platforms. How is this approach affecting suppliers?

Govindswamy: “If you can make a family or a modular design, I think that’s very helpful from the supplier perspective because one of the biggest barriers in the way of electrification going mainstream is cost. So, if you can make things modular or have a family of drivelines that work across a series of vehicles, this streamlines the entire engineering process and makes these designs much easier to scale up or down.

Does modularity help in terms of the offerings of electric motors that you would develop and integrate into your systems?

Renneker: “Yes, every volume manufacturer wants to use the constant of modularity or use as many of the same parts as possible. In the electrification space, this is much easier than it used to be for ICE. First off, there are fewer parts that you need to make, so the investment is not as high. And the scalability from 75kW to 400kW is a lot easier to do in electrification than it was in the ICE world. In my previous role with Ford, we had everything from a three-cylinder one-liter turbocharged gasoline engine in the smallest cars and a 6.7-liter diesel in our biggest vehicle. There’s no commonalty or scalability there because those vehicles were so radically different. Whereas with electrification it’s a lot easier to do that. Its diameter and length and how much current does your inverter produce. I think it’s an easier problem to do with on EVs that it had been. And of course, more modular we can be the lower price we can offer our customers and the faster electrification will spread.”

Do you see a problem with product differentiation as more BEVs enter the market?

Solt: “I don’t think so. We’ve got to remember that differentiation with brands includes styling, interior, ride, handling, cost, and unique features. There’s still going to be a tremendous amount of differentiation. It used to take a lot of money, engineering, and time to make high-performance vehicles versus economy vehicles. Now, the engineering differences between these high- and low-performance variants is minimal and there’s a lot of common parts. I think you’re going to see a lot of OEMs and their brands offer eco versions and performance versions because they can effectively flip a switch. So, I think you’re going to see a lot more competition in this sector when the smaller manufacturers can offer the same level of power.

How does the hybrid factor into the future of electrification?

Solt: “One of the things that gets overlooked when we talk about BEVs is that those figures are under nearly ideal conditions. It’s not zero degrees, your air conditioning isn’t running full blast, you’re not hauling a trailer up a grade. So, range is a big deal for some applications. A gallon of gasoline has 34.6 kWh of energy. For a battery, you need 20x the volume and 50x the mass for the same energy. So power is there, but energy is a different story. So, for long range and heavy hauls, there’s definitely an opportunity for this [hybrid] technology.”

Renneker: “Hybridization has to come. If we really care about reducing CO2, it is criminal to throw kinetic energy away. So, every vehicle needs to have some sort of kinetic energy recovery system. Now do you go all the way and go straight to BEV? That will be determined in the future but personally, I think you’re going to have a very large percentage of ICE-driven hybrids for a long time because they will be able to cover more use cases than BEVs.”