Hyundai Tech: Sonatas of Two Different Flavors

Hyundai is expanding its Sonata lineup seemingly with something for everyone. In honoring this South Korean company’s press embargo, I cannot share driving impressions just yet, but I can spill the technical beans. And there are lots of them.

The 2.0T Sonata, as its name suggests, is powered by a turbocharged 2.0-liter engine. Hyundai avoided the GDI moniker that could have legitimately been attached, as this inline-4 also features direct injection of its gasoline. Now I admit there’s nothing particular novel about having a turbo-enhanced direct-injected engine of small displacement do the job of a traditional—and more fuel-consumptive—V-6. But Hyundai engineers have been busy in perfecting this concept in several distinctly innovative ways.

For one, the turbo’s compressor housing is actually part of the engine’s exhaust manifold. What’s more, the casting that integrates these two elements is of austenite stainless steel. It’s quite a technical achievement to use this material, but it’s ideal for this application because of its thermal properties of getting exhaust heat efficiently to the turbo’s compressor. And, of course, having the two components integrated into one only enhances this.

Factoid: It’s both the kinetic energy of exhaust flow as well as the thermal energy of its expanding gases that drive the turbo’s compressor and its attached forced-induction-producing impeller. Hyundai’s integrated design enhances both aspects.

The Sonata’s turbo is a twin-scroll type as well. That is, its porting and vanes are designed to exploit two separate paths of exhaust flow, from cylinders 1 and 4 and from cylinders 2 and 3. This way, pulses during inherent four-stroke operation don’t trip over each other. This twin-scroll idea isn’t unique to Hyundai (the 2.0-liter Buick Regal uses it as well). But the Sonata’s 274 bhp versus the Regal’s 220 suggests the other wizardry involved.

Hyundai engineers figure that optimized forced induction plus direct injection are worth around a 22-percent kick in torque, from 220 to 269 lb.-ft. over a broad rpm range, with the twin scrolls accounting for perhaps half this. There’s lots of synergy involved here as well: Direct injection provides a cooler charge of fuel; optimized intercooling does its magic as well with the forced induction of air. They combine to produce the 2.0T’s 137 bhp/liter, a figure that’s quite amazing in a car in the $24K-$29K range. More details on this and my driving impressions once the embargo has lifted.

The Sonata Hybrid also carries some very neat tech, specifically in its parallel-hybrid drivetrain, lithium-polymer battery pack and optimized thermal management. Hyundai engineers also pointedly used the term “fun to drive” in describing their hybrid design and development.

Its 2.4-liter gasoline engine operates on an Atkinson Cycle; more correctly, like other hybrids, on a innovatively valve-timed simulation of this short-compression/long-expansion concept. A clutch separates this powerplant from a 41-hp electric motor which resides directly ahead of a 6-speed automatic transmission eventually sending twist to the car’s front wheels.

Note the difference between Hyundai’s hybrid layout and those of Toyota Camry, Ford Fusion or Nissan Altima (these three, certainly technical siblings in more ways than one). The Hyundai’s 6-speed automatic is in marked contrast to the other’s CVTs, one claimed benefit being enhanced highway performance. What’s more, as its operation is integrated with the electric motor’s, this automatic has no need for an energy-sapping torque converter.

Unlike these other cars’ nickel/metal hydride battery technology, the Sonata Hybrid’s is lithium-polymer. Newer technology, it offers improvements in everything from power and energy density to weight to volume to cycle life to characteristics of state of charge.

This last one, SOC, for short, is particularly interesting in Hyundai’s optimization of hybrid operation. For reasons of durability, any battery profits from gentle chemical action—not being discharged too deeply, not being charged to its full capacity, with SOC being a measure of this. Typical nickel/metal hydride batteries owe their life-of-the-car longevity to an SOC window as narrow as 15 percent; e.g., operating no less than 50 percent SOC, no more than 65 percent SOC. Hyundai engineers say lithium technology can accept a wider range, say 50 to 75 SOC, with no degradation of battery durability.

What’s more, innovative thermal management stretches this further: In cold weather, for example, the Sonata Hybrid’s SOC window can expand to as wide as 45 percent, from 45 to 90 SOC. One benefit of this is balancing the inherent loss of battery performance concomitant with lower ambient temperatures. Despite these exemplary SOC characteristics, Hyundai engineers expect to confirm battery longevity on the order of 250,000 miles or more.

A last example of Hyundai’s thermal management and efficiency. Compared with other Sonatas, the Hybrid has a larger air intake; this, to handle hybrid powertrain cooling in extremes such as Death Valley at summer’s peak. On the other hand, such a gaping snout is detrimental to aerodynamics. To optimize matters, the Sonata Hybrid has what engineers term an Active Air Flap. As its name suggests, this gizmo automatically adjusts the airflow. It’s wide open at low vehicle speed and high coolant temperature; it closes as speeds increase or coolant temperature drops. Engineers figure there’s a 10-percent reduction in CD with this, all the more impressive when you hear that the car’s inherent drag is an already low 0.25.

My driving impressions of the Sonata Hybrid can appear on October 18 (one day before my birthday—please, no presents).

We drive Mazda’s Norwegian hydrogen-powered RX-8

Yes. You read that correctly. Mazda has been experimenting with hydrogen as an energy carrier for a long time. In fact, I wrote about it way back in Tech Tidbits, July 1992. Not long afterward, Mazda offered me a drive of a special hydrogen-fueled rotary-powered Miata MX-5. More than a decade later, March 2004, Sam Mitani drove and was able to report on an RX-8; this one, dual-fueled, either gasoline or H2.
And, indeed, the latest version of this RX-8 HRE (as in “Hydrogen Rotary Engine”) is what I drove recently. The HRE has had lease-only availability in Mazda’s home market since early 2006. The car is also taking part in Norway’s Hynor Hydrogen Highway Project, in which seven stations support a 360-mile route from Stavanger, in the southwest of the country, across to Oslo.
Why a hydrogen rotary?
It turns out there are two excellent technical reasons for fueling a rotary with hydrogen, both based on combustion dynamics. "With a rotary's hmmmm, as opposed to a conventional reciprocating engine's boing boing, note that a rotary's engine's intake port is nowhere near its combustion chamber." Thus, unlike in a recip engine, the intake charge isn’t subjected to hellacious heat of the previous combustion.
This is of particular importance with hydrogen, because the stuff is 10 times more flammable than gasoline. A major challenge in hydrogen recip engines is “flashback,” essentially preignition of the H2 encountering hot surfaces. A rotary engine sidesteps this completely.
Another beneficial aspect of rotary combustion is its inherently greater swept volume. Intake and compression of a recip engine involve 360 degrees of crankshaft rotation. By contrast, the rotary’s eccentric shaft travels through 540 degrees to accomplish these same two cycles, thus giving a more consistent mixture of fuel and air.
In summary, rotary combustion and hydrogen are made for each other—more or less.
The “less” part has to do hydrogen’s volumetric shortfall as an energy carrier, combined with a rotary’s inherent paucity of low-end torque. As a general rule, if an engine has dual-fuel capability, it gives up almost half its gasoline output when running on hydrogen. In the RX-8’s case, a gasoline-fueled 206 bhp drops to 108 on H2; torque diminishes from 164 lb.-ft. to 103. What’s worse, the RHE is tuned to deliver this reduced output in either of its dual-fuel modes.
Alas, the RX-8 HRE’s performance is decidedly sluglike. This feels all the more disconcerting because the car’s driveability on either fuel is exemplary. What’s more, the rotary’s phenomenal smoothness in revving is retained—only the kick is halved.
What’s Mazda to do?
If it were me, I’d dedicate the engine utterly to hydrogen. Its high octane—effectively 130+—would permit really abundant forced induction, gaining back a lot of the lost output. Also, in forgoing the dual-fuel jazz, I’d replace the RX-8 HRE’s currently minuscule 6 lb. of H2 at 5000 psi with perhaps double the tank volume and also take advantage of state-of-the-art 10,000-psi storage.
The car would still be an excellent “bridge,” a much-needed transitional vehicle in helping solve the chicken/egg challenge of hydrogen mobility. With proper rotary smoothness and power, it would be all the more entertaining as well.
(Purely as an aside—and because people have asked—the rotary concept isn’t amenable to diesel. This has nothing to do with anything we’ve discussed here. Rather, the problem is the infeasibility of arranging a rotary’s compression ratio high enough for diesel compression ignition.)

The Mercedes-Benz Shooting Brake Wagon is a Go

When Mercedes-Benz unveiled the CLS Concept Shooting Break at the 2010 Beijing Auto Show back in April, the company erroneously named it a “Shooting Break.” It’s understandable, as the French call this type of car a “break de chasse,” and break is listed as an alternate spelling in some glossaries. However, anyone who grew up in the U.K. knows that a shooting brake is a luxury 2-door coupé (or less commonly a 4-door sedan) with a station wagon rear end. Of course in the U.K. the generic term for an ordinary station wagon is “estate car.”
Before the Second World War Shooting Brakes were popular with the landed gentry in the U.K. Because of this, “shooting brake” is the accepted name reserved, if you will, for luxury station wagons such as the handful of Aston Martin Shooting Brakes custom-made in the 1960s.
Fast forward to today and Mercedes-Benz has confirmed that it will produce the CLS Shooting Brake as a new model in 2012. The press release clearly calls it the CLS Shooting Brake. It’s an appropriate name that could easily have been attached to other recently launched luxury station wagons.
The second-generation 2012 CLS 4-door coupé, which was unveiled at the recent Paris Auto Show, has already garnered several rave reviews for its sleek lines. The new Shooting Brake barely alters the overall sweeping look despite the longer roof and tailgate.
While European buyers will have a wide choice of engines it looks as if the new 4.7-liter twin-turbo V-8 that is powering the 2012 CLS 550 will be the only choice, at least initially, in the U.S. when the CLS Shooting Brake goes on sale later in 2011. It produces 402 bhp at 5250 rpm and 443 lb.-ft. of torque from 1600-4750 rpm.
Like the CLS, the Shooting Brake will offer a barrage of safety items including 12 airbags and optional features such as a dozen driver-assistance systems to help prevent accidents and reduce the severity if one should occur. The Active Blind Spot Assist and the Active Lane Keeping Assist are new. The Shooting Brake will also have the same all-new electromechanical Direct-Steer system that is appearing first in the CLS.
One of the most interesting new options is the LED High Performance Active headlamps that Mercedes-Benz says are a world first. They are closer to daylight than Bi-Xenon lights, which Mercedes-Benz claims is less tiring, yet they produce as much light. Each headlamp contains 71 LEDs that can be adjusted in a variety of ways, including spreading light around corners. In addition, the left headlamp can be dipped independently of the right to improve the view for the driver while avoiding dazzling oncoming vehicles.
The Shooting Brake will be built on the same production line as the CLS, along with the E-Class upon which the CLS models are based, at the facility in Sindelfingen—Mercedes-Benz’s largest plant.

Recalibrating the Toyota Prius

I’ve recently driven the Chevrolet Volt and Nissan Leaf. Indeed, I’ve written items here and also did our print R&T’s Leaf First Drive and coming Road Test. These are important new cars, each likely to modify people’s views on personal mobility. A decade ago, another car did a similar thing, and now the Toyota Prius is in its third generation.
How does the Prius compare with these two new contenders in our Brave New Technology?
To recalibrate the car—and, in a sense, to recalibrate myself—I borrowed a Prius for the 10-day period including the Thanksgiving holiday as well as a trip to San Francisco. Here’s what I’ve found so far.
An assessment of interior roominess concurs with my memory. In terms of ingress/egress, driver comfort and even the ability “to sit behind one’s self,” my particular ordering is Prius, Leaf and Volt. A Full Disclosure here: As many readers know, I’m bigger than the average bear, have a disproportionately long torso and a less than agile back as well. Also, curiously, the driver seat has a height adjustment missing in the passenger seat of a Prius. As a front seat passenger, I have equal head room in Prius and Leaf. No contest, though, in the rear seat. I find the Volt’s head room interference back there to be well nigh claustrophobic.
All three are 5-door hatchbacks, a layout that I find very useful. Indeed, if I owned any of them, I’d likely fold the rear seats except when needed.
The contrast of performance among the three is strong. In its initial “charge depletion” mode, the Volt behaves like a pure electric. As such, it’s the quickest of the trio. Once in “charge sustaining” mode, its engine is relatively unobtrusive. This plug-in series hybrid is good, sound, innovative technology.
The Leaf’s performance isn’t far behind, and indeed I find it the sportiest of the trio. Alas, its inherent pure EV range makes it unsuitable for some missions, namely the San Francisco portion of my adventure.
At around 9.7 seconds 0 to 60, the Prius is the slowest of the three in acceleration. It’s also the least sporty to drive. In fact, though, its enthusiast involvement is of a different nature.
Around town, I encourage the Prius into electric propulsion whenever possible—subject to a simple rule: Never drive like a dork. I use the car’s gasoline engine, often almost at full throttle, to accelerate to ambient traffic pace, then lift off momentarily to finesse it into electric mode. This works fine in typical 45- to 50-mph suburban traffic, and it’s good fun to see the resulting high mpg.
The Prius’s EV mode is button-activated and keeps the car utterly electric. However, it limits speed to around 25 mph and acceleration as well. I found this mode useful only in parking lots, school zones and my immediate neighborhood. Indeed, I’d play a little game coming home from work: Entering the neighborhood (zoned at 25 mph anyway), I’d use EV mode to coax a couple extra tenths out of the mpg monitor before reaching my driveway.
There’s also a PWR mode button that evokes somewhat sharper throttle response. I tended not to use it. Indeed, I did most of my driving in ECO mode and found its somewhat heavier throttle more to my liking.
In town the Prius got low 50s mpg, depending on how the traffic around me was behaving. Remember my “no dork driving” rule; and, curiously, I was aware of other drivers expecting me to drive like one and maybe being surprised otherwise.
On my trip to San Francisco, I averaged 41.0 mpg through the Los Angeles freeway sprawl. Once into mixed motoring up Rte. 101, for a while there I set the radar-sensed smart cruise to just a tick less than the fastest cars (let them get the ticket). From Paso Robles to San Francisco, including the city stint to my downtown hotel, the Prius averaged 69 mph and returned 49.1 mpg.
Had I driven a Chevy Volt, it would have depleted its charge, likely within 25 miles at that highway speed. For the remaining 175 miles to San Francisco, its gasoline mpg would have been in the mid-30s at best. And, of course, the Nissan Leaf wouldn’t have worked at all for this particular mission.
Also, because I know some will ask, what about a diesel for this same adventure? It’s not in this trio’s clean-air league: A typical “clean diesel” is a Tier 2 Bin 5 vehicle by Environment Protection Agency rating, equal to only an average gasoline car. By contrast, the Prius is an AT-PZEV (Advanced Technology Partial Zero Emissions Vehicle). But for certification of its evaporative emissions, so likely is the Volt. And a Leaf is a ZEV (with its electric utility generating the only emissions).

Thus far, my recalibration of the Toyota Prius speaks favorably for this car and its technology.

Porsche 918 Spyder and 911 Turbo S Edition 918 Spyder Pricing Announced

With so much anticipation built up around the 918 concept cars—wantonly brandishing the Spyder and RSR race trim in the show circuit—Porsche would have been borderline unscrupulous not to bring the sexy hybrid into production. As it turns out, Porsche will build the supercar in its Spyder trim, carbon fiber-reinforced plastic monocoque and all. Except for the presence of a new roof (manually operated with removable panels that can be stowed in the front luggage compartment.
But before you rush to put down a deposit, the 918 Spyder is a bit more expensive than a 911. Listed at $845,000, it’s the equivalent of four and an eighth 911 Speedsters. But don’t let the numbers deter you, there’s so much more than fuzzy math to the 918. Take, for instance, its output. With a maximum estimated at 718 hp, it comes courtesy of a midship 500-bhp V-8 and two electric motors both good for 218 hp. Mounted on the front and rear axles, the electric motors act independently and endow the 918 with variable all-wheel drive.

Hybrid Powertrain, Supercar Performance
Fitted with a 7-speed twin-clutch gearbox, the 918 Spyder has some lofty performance targets: 0–60 mph in 3.1 seconds, a 199-mph top speed and the Nürburgring in under 7 minutes, 30 seconds—that’s 2 sec. quicker than the Carrera GT. And don’t forget, these numbers are for a plug-in hybrid. Porsche is throwing out efficiency figures of 94 mpg and 16 miles of range solely on its lithium-ion batteries.

Limited to 918 units, production for the 918 Spyder doesn’t start until September 18, 2013. Think 2013 holidays, if you’re well behaved. For the impatient types, there’s the 918 Spyder-edition 911 to hold you over.
911 Turbo S Edition 918 Spyder

If you can’t wait until late 2013, Porsche is placating buyers of the 918 Spyder by offering them an exclusive opportunity to purchase an “Edition 918 Spyder” 911. Based on the 530-bhp 911 Turbo S, the special-edition Porsche has carbon-fiber trim inside and out, plus upgraded leather, badging and the exterior colors of the 918, including the use of Acid Green on the brake calipers, illuminated sill plates, interior stitching and instrument cluster needles. Also limited to 918 units, the 911 Turbo S Edition 918 Spyder will be available in Coupe ($160,700) and Cabriolet ($172,100) forms, making this one very expensive dealer option.