CleanMPG Previews the 2010 Lexus HS 250h

Who would have thought that the sixth most fuel efficient vehicle available in the US and Canada might soon be a Lexus?

Wayne Gerdes - CleanMPG - June 16, 2009

2010 Lexus HS 250h – Preliminary estimates indicate 35 mpgUS combined on the 08 EPA with an starting MSRP of $35,075 including shipping.

Rochester, MI. -- With 170,000 Lexus hybrids already on the road, the HS 250h’s upcoming mid-summer release will be Lexus’ fourth (and only dedicated) hybrid following the RXh, GSh and LSh into the hybrid realm. Interestingly, the only Lexus vehicles waiting to be hybridized are the performance and convertible based IS models and large SUVs. Lexus could be the first manufacturer to offer a hybrid drivetrain in every category, and they appear ready to do so within the next decade.

Since a Hybrid Synergy Drive (HSD) equipped Lexus matches or exceeds the performance capability of its similarly displaced gasoline powered counterpart and offers world class fuel economy with an ever improving cost differential, a full hybrid lineup within the luxury marque makes perfect sense. Future CAFÉ’ requirements are bearing down on all manufacturers and it is no longer a question of “if” but rather “when” Lexus becomes the first brand to offer only hybrid vehicles across its entire lineup. An interesting proposition, indeed.

2010 Lexus HS 250h - Prospective Consumers

“More than 60 percent of current luxury car buyers would purchase a hybrid if one were available,” said Mark Templin, Lexus Group VP and GM. “Additionally, our target buyers for the HS 250h are looking for more luxury and performance at an affordable price.”

Not only is the HS 250h the company’s first dedicated hybrid, it was designed to be a premium luxury equipped hybrid sedan that is attractive to the 40-something demographic.

Lexus expects to sell 25,000 HS 250h’s through the first calendar year.

2010 Lexus HS 250h - Specifications and Trim Levels

The HS 250h will be available in two trim levels, Base and Premium. Standard appointments with either trim maintain the Lexus elite luxury lead and include an exceptional mix of features not found in lesser makes.

For the 2010 Lexus HS 250h’s general overview and specs, you can read both the “Details released” and Specifications and Trim detail pages.

Both the 2010 Lexus HS 250h - Technical Presentation and details of the optional 2010 Lexus HS 250h - Mark Levinson Audio Info docs can be downloaded from the files section of CleanMPG.

2010 Lexus HS 250h - New and Interesting Features

In addition to an almost overwhelming number of features and amenities listed in the Technical Presentation and Specification pages, there are a number of both minor and major additions we would like to highlight.

Build Quality

Toyota and Lexus craftsmen are masters when it comes to automobile Quality Control. A striking example of their attention to detail can be found within a facility located in Kokura, Japan which is dedicated to the production of hybrid drivetrain sub-assemblies. Not only is the inside of this plant temperature and humidity controlled, the air quality and pressure are precisely controlled to eliminate particulate waste from both the end of the production line (highest pressure) and the beginning stages (lowest pressure). The entire line is kept above external atmospheric pressure and the environment is continuously monitored in order to prevent all possibility of contamination.

The sedan itself is assembled at the automaker’s facility in Kyushu, Japan.

Environmentally friendly materials

Approximately 30% of the interior and trunk trim are made from plant-based ecological plastic.

• Upholstery parts include internal trunk trim, trunk lid trim, and the rear combination lamp cover.
• Injection Molded parts include the Cowl side plate, Door Scuff Plate, tool box, and finish plate.
• Foam parts in include the lower seat cushion bottoms.

Aerodynamics explained

Why should Lexus copy the three bar grille design from the Honda Clarity, Insight-II, and Ford Fusion Hybrid? For aerodynamics of course!

Manufacturers have found that at low speed air will flow through the individual bar openings while at higher speed a boundary layer is formed which smooths air flow across the gaps and up over the hood.

Most know that under-body covers are standard fare on Toyota’s hybrid offerings. The HS 250h uses an independent rear suspension setup which is vastly superior to the Torsion beam unit found in the 2010 Toyota Prius-III, but its lower control arms cannot be tucked up and out of the way as neatly. To reduce drag, Lexus spent the dollars and attached aerodynamic panels to them. This is quite simply an amazing attention to detail.

Chassis

The 2010 Lexus HS 250h is built upon the Toyota NC platform underpinnings of the 2010 Prius-III and the 2009 Avensis (offered in Europe). Think of the Lexus HS 250h as a luxury and performance based Prius under a beautifully sculpted sedan shell. The independent rear suspension setup described above is different however, and it is implemented at the expense of trunk volume. This suspension does not include the traditional dual sided upper wishbone but instead uses a single arm attached through a beefed up knuckle.

Shod with 17 or 18” rim and tire combinations, the Lexus is taller than the Prius-III but offers nearly identical headroom.

HSD’s evolution

With each new hybrid vehicle, the Toyota/Lexus contingent evolves. The first generation Prius offered 273V exiting the Inverter directly while the Prius-II’s 200V pack provides power through an up-convert to 500V. The TCH utilizes a gear reduced MGSet and the HiHy up-converts its pack voltage to 650V. The latest RXh implements an Exhaust Heat Recirculation system. To these innovations Lexus now adds the 42-Volt EPS system included in its HS 250h. This system allows lower current and improved reliability with additional feedback programming.

Safety

The adaptive front lighting system handily exceeds the capabilities of pivoting headlights featured by other luxury vehicle manufacturers. In addition to illuminating the road surface in turns ahead of the vehicle, the system has another unique function called “Intelligent Hi Beams”. The high beams automatically transition back to standard headlamps when approaching oncoming vehicles as far as 2,625' away, and they exhibit the same behavior when approaching another vehicle from the rear at up to 2,000'. Sensitivity can be adjusted via the multi-information switch.

The technology package includes Dynamic Radar Cruise and Lane Keep Assist, but another advanced innovation is also added. A driver face mapping function utilizes one of the two cameras included with the package; one mounted behind the rear view mirror and detects lane-markers ahead while the other is mounted on the steering column and detects a drowsy or distracted driver.

Just under the Lexus badge on the hood is a forward looking camera that not only looks ahead but also to the side for an astonishing 190 degree field of view. Although the NAV screen compresses this down to a 90 degree display mimic, it works extremely well.

Infotainment and the Human Machine Interface

As in all other Lexus vehicles, the NAVI unit can only be manually programmed to a new address while stopped. Mitigating this shortcoming is the all-new Lexus Enform system. This allows you to call an exclusive “Destination Assist” operator via the included cellular system to have a new destination uploaded to your car while underway. There are enough features included in the system to fill a large instruction manual, so we won't describe more of them until CleanMPG has the opportunity to drive the LS 250h for an extended period of time. Please download the technical presentation linked above for a description of all the features available in the Lexus Enform with Safety Connect system.

A “Haptic” (force-feedback) remote controller will become the norm for all future NAVI equipped Lexus vehicles. The Haptic interface is a mouse like controller which not only replaces touch screen functionality but also provides sensory feedback tied to specific graphical elements the mouse cursor is hovering over.

Now that we have those details out of the way, let's go for a ride!

2010 Lexus HS 250h - Basic Competitive Comparisons

Year	Make	Model	MSRP	Passenger Volume (cu. ft.)	Cargo Volume (cu. ft.)	08 EPA combined (MPG US)
2010	Lexus	HS 250h	$35,000*	90.2	12.1	35
2010	Acura	TSX	$29,310	94.5	12.6	25
2009	Audi	A4 2.0	$31,000	91	16.9	23
2009	BMW	328i	$33,600	92	12	22
2009	MB	C 300 Sport	$32,900	88.3	12.4	21

* Estimated. Actual pricing release scheduled for late summer 2009.


2010 Lexus HS 250h in Black Opal Mica looks almost ready to race.

2010 Lexus HS 250h - Comfort, Convenience, and Ergonomic Impressions


A warm and inviting interior greets you every time you sit behind the windscreen.

Due to the large number of journalists and limited supply of HS 250hs our time in the vehicles was restricted to less than an hour. I drove one loop and rode for another -- after such a short time with the car my impressions are positive but will have to be confirmed with a later, more extensive set of driving tests.

The driver's seating comfort after adjustment is nothing short of fantastic. The Prius-III’s ergonomics are still not quite right with the steering wheel reach just an inch too long even with the telescopic wheel fully extended. In contrast, the HS 250h feels like a comfortable and well worn leather glove. Adding to the feel of luxury, the HS 250 provides the soft feel of leather on its steering wheel while the lower level Prius-III arrives with a rough rubber like texture. A breath of fresh air indeed.

What is not so pleasant however is the sensation of being slightly restricted in the HS. Comparing interior specs, the Prius-III and HS 250h are all but identical when the Prius-III is equipped with a Solar roof. The feeling of airiness when sitting in the Prius simply doesn't exist in the Lexus. This is likely due to the large C-Pillars and sedan form factor. Unfortunately, when in the most relaxed driving position I found the HS 250h’s E-Flashers and shift lever were not in ergonomic positions. The vehicle displays (including Touch Tracer) were also not in the proper lines of sight while seated in this position.

The lack of a complete HSI (Hybrid System Indicator) with an EV Threshold (such as the one found in the Prius-III) was also sorely missed... though most HS 250h purchasers will never know what they are missing.

A plus for the HS 250h is that Lexus allows cycling back and forth between two or more user chosen displays rather than requiring tedious stepping through all available screens.

I did not get a chance to drive the Navigation and Technology package equipped HS 250h but did ride in it as a passenger and was not able to see the HUD. I did experiment with the “Haptic” remote controller for two or three minutes and in that brief period, I did not get accustomed to its feel. Many journalists berate BMW and its iDrive system and I must admit, so did I for the first hour of use during the BMW 335d Review. After that period of time however, I found the iDrive’s solid click and feel to be one of the best systems experienced to date. The Lexus “Haptic” solution has too light a feel for my liking and has very little feedback when hovering over a selection. With more seat time, the Lexus amenities will undoubtedly prove to be “best in class”.

As with all upscale automobiles, the Lexus HS 250h does not disappoint with its warm presentation for occupants and a soft tactile feel on every surface and control.

2010 Lexus HS 250h - Performance, Handling and Fuel Economy

The HS 250h’s basic straight-line performance is largely due to the Atkinsonized 2.4L engine sourced directly from the Camry Hybrid. Entirely new to the Lexus lineup this year is Toyota’s all-new sixth generation HSD -- it allows a full one mpg improvement over the Camry despite a similar curb weight. The more powerful 2.4L allows the HS 250h to achieve 60 mph about 1.3 seconds sooner than the lighter, 1.8L equipped 2010 Prius-III -- and does so with far less engine noise. Though it is quieter, the HSD still forces the ICE to rev up noisily before hard acceleration occurs... just as it has in all other THS and HSD equipped Hybrids. This is something that could only be remedied with a more powerful battery pack, unfortunately.

I only took one corner at about .35g so I couldn't say if it will under-steer, over-steer with a tail wag following (expected), or drift smoothly into and out of a transition. It does feel awfully heavy, though. Whether this is due to EPS programming or simply the fact that the HS 250h’s weight distribution is heavily biased to the front end (61% Front/39% Rear) is uncertain.

I was in a 15” wheel and tire equipped 2010 Prius-III taking on and off-ramps the day before and the HS 250h handles better due to tires alone. The 17” wheel and tire combination equipped Prius-III will probably hold its own against the much heavier HS 250h in the twisties or on a slalom course.

Fuel economy has always been an HSD equipped hybrid's strong point. With the all-new 6th generation HSD, the 250h's strengths include full hybrid mode glides up to 45 mph, warp stealth, warp neutral, and some limited EV travel. Using these basics properly easily allows drivers to achieve what some would consider astounding fuel economy in the luxury sedan.

With each new iteration of HSD there is a little more to be gained and the latest HS 250h proves to be no exception to the rule with its implementation. Lexus vehicles utilizing this latest generation powertrain will easily best any diesel or conventionally powered automobile of similar size and equipment around town when it comes to fuel economy. On the highway, even the current and upcoming super diesels will have trouble matching its efficiency because this newest system allows such low cruising RPM.

57.9 mpg over 18.3 miles.

The above was achieved on a drive with 2-miles of stop light to stop light segments and 16 + miles of 35 to 55 mph limited rural roadways sprinkled with stop signs every few miles. Who can complain about this kind of fuel economy while surrounded by one of the most technologically advanced, aesthetically pleasing, and safest vehicles one can drive and soon... money can buy?

2010 Lexus HS 250h - Preview Conclusions

My limited time behind the wheel was not enough to get a good feel for the vehicle and with the preponderance of advanced technology available, impressions and conclusions should be taken lightly until we receive a review unit for a short road trip later this year.

Along with the driving impressions described above, fit and finish, driver comfort in all realms of operation, and advanced technology were over the top -- something that should be expected of any luxury marque. What every other premium vehicle lacks however is the HS 250h’s environmentally friendly design and chart topping fuel economy capability.

Curt Mcallister and Paul Williamson standing next to the mighty Lexus HS 250h.

I want to extend thanks to Curt McCallister, Mona Richard, and Renee Socia for the invite and also for taking care of my arrangements for the Lexus HS 250h short lead preview.

I would also like to thank both Mark Templin and Paul Williamson for taking the time out of their busy schedules to give the marketing and technical presentations respectively. I would be remiss for not mentioning the STI individuals behind the scenes cleaning the vehicles to showroom condition time and time again. And of course our own Sean Welch for his work editing this preview experience.

A slideshow of the entire grouping of HS 250h pics can be seen in the following gallery: Lexus HS 250h Interior and Exterior.

Wayne