Hyundai and Efficient Electrification

Gary S. Vasilash

Through a platform strategy and efficient engineering, Hyundai has launched a suite of highly efficient electrified vehicles.

As Mike O’Brien, vice president of Corporate and Product Planning, Hyundai Motor America, has it, when it comes to “green” vehicles—meaning seriously electrified vehicles, be they gas-electric hybrids, plug-in gas-electric hybrids, or fully electric vehicles (EV)—the real metric needs to be efficiency.

While that might seem to be the case given the nature of the vehicles—which generally have miles-per-gallon numbers that leave non-electrified vehicles gasping—and the nature of the people who often buy these cars and crossovers—who are oriented toward reducing the amount of fuel used (and if they’ve opted for the EV, the amount of liquid fuel is, of course, zero)—that it should go without saying that efficiency is the thing, O’Brien disagrees. Especially, he suggests, when this comes to EVs which, he says, are suffering from a perception that was born in the early days of the vehicles, when batteries weren’t all that capable and the availability of fast-charging stations was pretty much nil and so people began to focus almost entirely on range, which gave rise to the phenomenon of “range anxiety,” which is still something of a malady, or at least so it seems to be, given the advertising messages that talk about EVs.

“The market awareness,” O’Brien says, “is of old EVs.” When batteries were limited and fast-chargers were few and too far in between.

What’s new
The Hyundai Ioniq Electric is a new EV. It features a 28-kWh lithium-ion polymer battery that provides an estimated driving range of 124 miles and an electric motor that produces up to 88 kW (a.k.a., 118 hp) and 218 lb-ft of torque.

The Ioniq Electric has an EPA-estimated 136 MPGe rating—which makes it the most efficient EV out there. That is, the 60-amp version of the BMW i3 has an MPGe of 124. The Chevrolet Bolt and the Volkswagen eGolf both come in at 119. The 94-amp i3 is 118. The Nissan Leaf, Fiat 500 e and Mitsubishi i-MiEV are all at 112.

However, one might point out that the Chevrolet Bolt, the 119 MPGe notwithstanding, has an estimated range of 238 miles on a charge, or 114 miles more than the Ioniq Electric.

While O’Brien acknowledges that, he points out that when it comes to gasoline powered cars, for those who even care about it (versus, say, the styling and the equipment and the amenities and the brand, etc.), the consideration is of miles-per-gallon. “We need to think about that more when it comes to electrified cars,” O’Brien says, adding, “No one looks at the size of a fuel tank on a car.”

And to the point of overall range, John Shon, Hyundai Motor America’s senior manager, Product Planning, notes that more than 98 percent of Americans won’t drive more than 100 miles on any given day. He also says that with an MSRP of $29,500, the 114 additional Bolt miles come at a cost: it has an MSRP of $36,620.

Still, there is the issue of range that can’t be overlooked by any OEM that is in the EV space. Hyundai is working with ChargePoint, which is said to be the world’s largest electric vehicle charging network, with 32,000 charging locations, and more than 400 fast-charging sites. DC fast-charging (80 percent of charge within 23 to 30 minutes) is standard with the Ioniq Electric.

O’Brien goes back to the point of efficiency. Yes, he says, they’re working on a battery that’s bigger, a battery that will be used in an EV with a longer range. “But it will not be as efficient.” In other words, they believe that with the Ioniq EV they’ve hit the sweet spot.

The platform approach
While launching an EV might be in and of itself significant, Hyundai has done more than that. What they’ve accomplished is the development of three distinct vehicles on a single platform. In addition to the EV, there are both the Ioniq Hybrid and the Ioniq Plug-in Hybrid. So with a single platform, they put themselves in a position to compete with an array of vehicles, as in hybrids: Toyota Prius, Ford C-Max, Kia Niro; plug-ins: Prius Prime, C-Max Energi, Chevrolet Volt; EV: Nissan Leaf, Bolt, Ford Focus Electric and VW eGolf.

Arguably, this approach is somewhat analogous to having a car that is available with a four-cylinder engine, a six-cylinder or a turbocharged four. Hyundai is providing variety within a single vehicle. Presumably, this is done, in part, in order to achieve greater scale than would be the case were it to have individual platforms for each of the vehicles.

O’Brien acknowledges that in 2013 the industry share of hybrid/plug-in/EV sales combined was 3.8 percent and that while the number of vehicles in these categories have increased, in 2016 the market share was actually down to 2.87 percent. Consequently, scale is all the more important.

What’s more, having vehicles of this nature is important for a number of other reasons. While there is the possibility that the EPA’s 2025 CAFE requirement will be modified (eliminated?) due to the current Administration, there are still the California Air Resources Board Zero Emission Vehicle Standards in place (and not likely to change) not only in California, but the other states following California’s lead (there are 16 either fully in or adopting the standards).

In California, the percentage of sales of a given manufacturer must meet the ZEV standards is 22 percent starting in 2025. This is a ramp up, with the number for model year 2018 being 4.5 percent. Given that aforementioned 2.87 percent, Hyundai, as well as the rest of the OEMs, are going to have to up their game for electrified vehicles.

Coming to be
According to Ki-San Lee, vice president, R&D, Hyundai Motor Group, the development of what became the Ioniq began in earnest in South Korea in the spring of 2005. The executives at the company recognized that they were way behind companies like Toyota, which had introduced the Prius in 1997. So they set about the development of the platform that would be the Hyundai basis for e-mobility.
At the time, he was the director of gasoline engine development. He was given a team of 32 engineers who, he says, “Had no hybrid experience.” They didn’t start with a set number as a target. Rather, he says, it was about being “the best in fuel economy or efficiency.”

As is expected, the Ioniq Hybrid and the Plug-in Hybrid have plenty of things in common, though it is worth noting that the fundamental vehicles for all three are the same, and all have an impressive coefficient of drag of just 0.24.

The setups
The two hybrids have a 1.6-liter, direct-injected, Atkinson-cycle four-cylinder engine that produces 104 hp and 109 lb-ft of torque. One massive achievement goes to the point of efficiency: the thermal efficiency of the Kappa engine is 40 percent. To put that number into context, know that the thermal efficiency of a typical internal combustion engine in a modern light duty vehicle is on the order of 25 to 30 percent.

Both hybrids also have a six-speed double-clutch transmission and it is said to provide best-in-class transfer efficiency through the use of low-friction bearings and low-viscosity transmission oil. Of course, given that most hybrids use continuously variable transmissions, the best-in-class claim is probably not as significant as is the fact that the Ioniqs perform more like non-hybrid sedans. But there are differences, too.

The Hybrid has a 32-kW (43 hp) electric motor that provides 125 lb-ft of torque. Combined with the engine, the overall system output is 139 hp. The electric motor is connected to a 1.56-kWh lithium-ion polymer battery that’s positioned under the rear passenger seat so as not to reduce cargo space in the rear.

The big difference with the Plug-in Hybrid is that it has a bigger electric motor—45 kW (60 hp)—and a bigger battery pack—8.9 kWh. This results in an all-electric range of approximately 27 miles.

A word about both the motor and the battery, something that translates across all of the models. One of the ways to achieve efficiency—and this is all the more important for electrified models, when you’re looking to get as much as you possibly can out of the available energy—is to minimize mass. So in the case of the permanent magnet synchronous motors used, they engineered them to be as much as 10 percent thinner than the components typically found in such motors; they’re using rectangular-section copper wire so as to maximize the package efficiency.

As regards the battery packs, according to Hyundai the lithium-ion polymer pack used in the Ioniqs is 20 percent lighter than non-polymer packs. What’s more, the polymer packs can be more readily shaped to meet package constraints.

The Ioniq Hybrid is offered in three trim levels: Blue, SEL and Limited. The Blue model has an EPA-estimated 58 mpg combined, which is the highest rating of any non-plug-in vehicle on the U.S. market. (The SEL and Limited are 55 mpg combined, so it’s not like they’re not efficient.)

Materials matter
One of the things that they addressed in developing the Ioniq is to have a car that rides and handles like, well, a car. So the Hybrid and the Plug-in have a multi-link rear suspension system with dual lower control arms. To minimize mass, there are several aluminum suspension components in both the front and rear. In the front, for example, there is a weight save of 13 pounds and a mass reduction of nine pounds in the back. And the aforementioned packaging of the battery pack below the rear seat also has the consequence of lowering the center of gravity, which improves ride and handling.

Aluminum is also used, it should be noted, for the hood, which is a weight save of 14.4 pounds compared with steel (mass of the aluminum hood: 16.5 pounds), and for the liftgate, which is a weight save of 13.5 pounds (mass of the aluminum liftgate: 16.5 pounds).

And the steel that is used for the body-in-white is both strong and light: 14.6 percent is 150 K; 14.1 percent is 100 K; and 24.8 percent are advanced high-strength steels from 60 K to 80 K.

They’ve also increased the use of structural adhesives. The Ioniq is approximately the same size as an Elantra. That is, the Ioniq and Elantra both have a 106.3-inch wheelbase, though the Elantra is longer, at 179.9 inches compared with the Ioniq at 176 inches. Both of those vehicles are smaller than the Sonata, which has a 110.4-inch wheelbase and which is 191.1 inches long.

However, when it comes to the use of structural adhesives, the Sonata has 390.4 inches. The Elantra has 393.7 inches. And the Ioniq has 475.7 inches. The phrase “increased use” doesn’t begin to do that justice.

And then there is torsional rigidity, which is achieved through a variety of means, including reinforcing the connection structure of the underbody and side body. As measured in 104kgf·m2/rad, the Elantra is 26.8, the Sonata 28.7 and the Ioniq is 29.2.

In developing the suite of Ioniq vehicles, they looked at everything. In the hybrids, there is no stand-alone 12-v lead-acid battery to accompany the internal combustion engine; the functionality of that battery is integrated into the hybrid battery pack, for a weight savings of 26 pounds. There is a spring on the brake pads to assure that there is no drag once the pedal is lifted. They’re making extensive use of bio materials like sugar cane in the interior of the vehicle—fabrics contain as much as 20 percent and the soft-touch surfaces are TPO with 25 percent sugar cane.

A final word about efficiency. It comes down to the price to drive. So they looked at the EPA figures for the overall cost to drive a vehicle 25 miles. In the EV arena, it costs $0.92 for a Bolt and $0.97 for a Leaf. It is $0.81 for the Ioniq Electric.

In the hybrid space, the Prius Eco is at $1.04 and the C-Max $1.46. It is $1.00 for the Ioniq Hybrid Blue.

That’s the efficiency that the aluminum, adhesive, lithium ion polymer, slippery surface and the rest help deliver.