Lexus: A Hatch This Time

Gary S. Vasilash

It's been about five years since Lexus had a hatch, the IS SportCross. But with the CT 200h, it is bringing to market a hatch with a difference: it's a hybrid.

Another year, another Lexus hybrid. While that may not be precisely true, that has pretty much been the case for the past several years. That is:

  • 2005 RX400h, a cross-over
  • 2006 GS 450h, a performance sedan
  • 2007 LS 600h L, a luxury sedan
  • 2009 RX450h, a new model of the 2005 product
  • 2010 HS 250h, the first-ever purpose-built luxury hybrid sedan

And now:

  • 2011 CT 200h, a compact sedan

And while on the subject of dates, it is worth listing off some of those of Osamu Sadakata, chief engineer for the CT 200h, who joined Toyota Motor Corp. in 1983 and who holds—and what could be better for a Lexus engineer—a masters degree in precision engineering from Shizuoka University Graduate School of Science and Engineering:

  • 2003, chief engineer for the RX 400h
  • 2005, chief engineer for all Lexus hybrid vehicles
  • 2008, chief engineer for the CT 200h

A point that should be kept in mind about this is the depth of experience that is being accumulated. Sadakata, while talking about the CT 200h, acknowledges, "The wide range of hybrid vehicle experience was helpful in the development." What's also helpful is the fact that the fourth-generation Lexus hybrid drive system is being used in the RX and HS models, as well, so there is a wealth of understanding of how to adjust the performance of the system to meet varying needs (e.g., with a crossover being different from a sedan that is focused mainly on fuel efficiency which is different from a compact hatch that is meant to provide spirited performance while still having respectable miles per gallon figures, with an estimated 42 city and 41 highway).

What's more, there is something of the reflection of the chief engineer's interests and personality in the car. He is a man who likes to spend time behind the wheel of a car. Of the CT, he says, "Enjoyment of driving is what I want owners to experience with CT. True driving enjoyment—to cater to all the senses and personalities. We gave it sport and eco driving modes, each with own distinct personality. Like the driver owns not one, but two vehicles. Not designed to be a sports car, engagement and responsiveness for driving enthusiast." And one aspect of this sportiness is the fact that this is the first hybrid with a tachometer (when it is switched into the Sport mode, the gauge to the left of the speedometer goes from being the "Hybrid System Indicator" to tachometer).

Given that the number of hybrid sales is almost correlated with gas prices—gas goes up and so do hybrid sales—and given that gas prices have gone down from their peak of a couple years back, Mark Templin, Lexus vice president and general manager, acknowledges that when the planning was being done for models including the HS and the CT the prevailing global economic conditions were such that petroleum use was sufficiently high that it seemed as though gas prices were going to do nothing but rise with growing global consumption. The worldwide economic downturn, however, reduced the amount of demand for gasoline, so the rise had not been what they'd expected. Still, Templin acknowledges that products like the CT 200h "represents a long-term play," indicating that the company that is still a comparatively young 21 years old intends to have viability—and desirable product—when gas prices begin what is likely to be an inexorable climb.

But there is another aspect to the CT 200h, which is that Lexus is a global brand. Although it had its start in the U.S., there are other markets that matter. Consequently, a car like the CT 200h has the potential to increase the sales in European countries, given not only the size of the vehicle (it has an overall length of 170.1 in.; a wheelbase of 102.4 in.; a height of 56.7 in.; and a width of 69.5 in.), but that it is a hybrid, and while European drivers have long favored diesels rather than hybrids, emissions regulations may make hybrids a more interesting choice.

In addition to which, Templin acknowledges that in the U.S. they're looking for the increasingly affluent portion of the buying public—which isn't the Baby Boom-generation, which is actually beginning to experience life on fixed incomes. So while the Boomers allegedly don't care for hatch architecture, the targeted cohort among the Gens X and Y don't seem to have this bias against the hatch. If the Boomers built the brand, then it is the groups following that will sustain it: Templin estimates that about ¾ of the sales for the CT 200h will be to buyers new to the brand. It competes in the premium compact segment that includes the Audi A3, Volvo C30, and BMW 1-Series. Templin admits that this is "a very small segment" of the market, with monthly sales fewer than 1,500 per month. But he has great hopes for the CT, saying that they hope to sell—because "it is a game-changer for the segment" (i.e., you can get a diesel for your A3, but you can't get a hybrid in any of the others)—1,000 per month. Something like $4.00 per gallon ought to make this more likely.

The CT 200h is a "hybrid-only" platform, although there are elements taken from other Lexus (and Toyota) underpinnings: their way is not to do reinvention but improvement through specific redeployment. This means that the engineers looked to optimize the vehicle while paying strict attention to making it fit to purpose. This not only relates to the hybrid system—it has the same 1.8-liter four cylinder Atkinson cycle engine, transaxle, and gear sets used in the Prius and the 134-hp total system output—but according to Paul Williamsen, national manager, Lexus College, the power electronics are modified for the CT 200h driving modes.

Or as chief engineer Sadakata colorfully puts it, "While the hardware is the same as with the Prius, as in cookery, a chef may use the same ingredients but come up with different things. We use the same parts to build the Lexus, but there are differences regarding what they do. This powertrain control unit can adapt to four different driving modes."

But powertrain aside, a big challenge faced by the Lexus engineers was developing the body and chassis, providing a vehicle that carries 28 nickel-metal hydride batteries under the trunk floor as well the engines and the motor-generators with a sense of sportiness. Williamsen: "This is very much about driving dynamics, not 0 to 60." (The car has a top speed of 113 mph and a Lexus-measured 0 to 60 mph of 9.8 seconds. And it is capable of driving for about a mile at up to 28 mph in pure electric mode—depending on several variables, like state of charge of the batteries, climate, etc.)

Which meant to achieve the sort of dynamics they were looking for, they spent a considerable amount of time performing CAE analysis of the structural components, which led to a number of structural, manufacturing, and material decisions. One of the challenges of a hatchback design (which is in some ways analogous to what's faced when developing a convertible) is the large open area in the back for the hatch opening reduces body rigidity (just as cutting off the roof does to a convertible). So to make the structure stiff, a number of things were done, including:

  • Deploying an abundance of spot welds to connect the rear floor cross member to the wheel housings
  • Adding braces to the suspension members where the suspension is attached to the vehicle
  • Using a fully closed cross sectional frame around the circumference of the rear opening
  • Reinforcing the quarter pillar area so there are split/folding rear seats without requiring a partition panel or upper back panel.

However, one of the down sides of making a structure stiff is that by adding things like reinforcements, overall weight can go up. So a considerable amount of high-tensile strength sheet steel was used—as high as 142,000 psi, although the door intrusion beams are even higher: 213,000 psi. What's more, there is more aluminum used in the CT 200h than for any other Lexus sedan, including the hood, bumper reinforcements, and back door.

The car is engineered with a low center of gravity and with a weight distribution of 40% rear, 60% front. And it is designed with a coefficient of drag of 0.29.

The issues that remain are not whether Lexus will be able to get a sufficient supply of CT 200hs from the Kokura hybrid-only plant in Kyushu, Japan, but whether there will be a sufficient demand for the hatchback, particularly in the U.S. In Europe, where Lexus had the world premier of the car, the vehicle style was as common as fashionistas, so there should be no problem there. And while gasoline prices continue to be moderate in the U.S., most Europeans probably wish that their fuel was at a $4.00/gallon price point.