Buick Regal and LaCrosse eAssist 2012
LaCrosse is a long wheelbase Regal
Buick has a hybrid (not a lot unlike the GM BAS from
2007) that they call eAssist. Fuel economy is 26 mpg
city and 36 mpg on the highway. It is a high voltage BAS
with a water cooled belt driven brushless motor. In
2012 the Regal eAssist sold for about $30,000.00 US.
One interesting part of the story is that there is no
external badging that says anything about this being a
hybrid. You see the average Buick owner is a senior
with little to no interest in hybrids. At the San Francisco
auto show in 2011 I asked the Buick saleswoman at
their booth if the Regal with the orange cables under
the hood was a hybrid? Her answer “No but it has some
hybrid parts in it”. Politics is everywhere.
What Makes the Regal Different from
the LaCrosse
The wheelbase is the main technical difference
between the two cars. The Regal is 107.8” vs. 111.7” for
the LaCrosse, so you might call the LaCrosse a
stretched Regal. The hybrid system is the same. The
cars start out at about the same price point but the
LaCrosse has almost 20K in added features one can buy
getting the total to almost 50K.
The Dash Board Video Game
What GM Had to Say
Regal with eAssist joins the 2012 LaCrosse as the
second Buick to feature the efficiency-enhancing
technology. The system uses a state-of-the-art lithiumion battery system, electric induction motor-generator
and regenerative braking capability to improve fuel
economy. “Buick’s eAssist technology means customers
don’t have to trade a premium driving experience for
efficiency,” said Tony DiSalle, vice president of Buick
marketing. “We believe Regal and LaCrosse with
www.fixhybrid.com • 800-939-7909
79
Buick Regal with eAssist
eAssist provide more logical and affordable choices,
compared to other hybrid midsize and full-size luxury
sedans.” The eAssist went on sale in the fall of 2011.
Drivetrain
Mated to Regal’s 2.4L Ecotec direct injection fourcylinder engine and next-generation six-speed
automatic transmission, the eAssist system uses power
stored in the battery to provide needed electrical boost
in various driving scenarios, optimizing engine and
transmission operation. An advanced 115 volt lithiumion battery and latest-generation 15-kW induction
motor-generator unit help increase fuel economy with
the usual regenerative braking, which provides up to
15 kW of electricity to charge the battery and provides
up to 11 kW (15 hp) of electric power assistance during
acceleration. The automatic engine shut-off when the
vehicle is stopped and fuel cut-off during deceleration
down to zero vehicle speed, enabled by the torque
smoothing provided by the induction motor-generator
unit, makes the car green and Intelligent. The charge
and discharge of the high-voltage battery is typical
hybrid fare and helps deliver electric boost to the
80
powertrain system during heavy acceleration and
grade driving enabling the engine and transmission to
operate more efficiently.
Regal with eAssist technology also features improved
underbody aerodynamics and tires optimized for
performance and fuel economy. It also features a hillassist system that captures brake pressure to help the
driver more comfortably accelerate from a stop on a
moderate or steep grade. It does this by greatly
reducing the tendency of the vehicle to roll backward
with the engine in shut-down mode.
While in fuel shut-off mode, the induction motorgenerator unit continues spinning along with the
engine to provide immediate and smooth take-off
power when the driver presses on the accelerator.
Then, as the vehicle comes to a stop, the induction
motor-generator unit spins the engine, bringing it to a
smooth stop – properly positioned for a smooth restart.
The eAssist power pack contains the lithium-ion
battery pack, the integrated power inverter and 12 volt
power supply. It is located in a compartment between
the rear seat and trunk; and it is surprisingly compact
and lightweight, weighing only about 65 pounds (29
www.fixhybrid.com • 800-939-7909
15-kW induction motor-generator unit
The driveline of eAssist by Buick, a division of GM.
kg). Trunk space is slightly reduced when compared
with 2011 models with the four-cylinder/six-speed
powertrain, but still offers 11.1 cubic feet (314 liters)
of storage. A quiet electric fan cools the power pack,
drawing air from a vent located in the package tray,
behind the rear seat.
The eAssist system’s electric induction motorgenerator is mounted to the engine in place of the
alternator to provide both motor assist and electricgenerating functions through a unique engine
belt-drive system. The induction motor-generator is a
high-performance, compact induction motor that is
liquid-cooled for increased performance and efficiency.
Next-generation six-speed
The eAssist system works with Regal’s direct injected
2.4L Ecotec four-cylinder and next-generation sixspeed automatic powertrain combination. In the Regal
with eAssist, the engine is rated at 182 horsepower
(136 kW) and the next-generation Hydra-Matic 6T40
features make the powertrain more efficient.
Significant internal transmission changes to clutch
controls and hardware provide reduced spin losses
while improving shift response and time. The added
electric power provided by the eAssist system allows
for higher gearing to improve steady state efficiency
115 volt air cooled Li-ion Battery Pack
without impacting acceleration performance or
driveability. The system’s ability to provide some
electric assistance at cruising speeds allows the driver
to accelerate lightly or ascend mild grades without the
transmission downshifting.
An auxiliary, electric-driven transmission oil pump is
added to the 6T40, which keeps the transmission
primed and the fluid flowing when the engine shuts
down at a stop. That keeps the transmission ready to
perform when the driver accelerates, for a seamless,
uncompromised driving experience.
www.fixhybrid.com • 800-939-7909
81
eAssist High Voltage Drive System
The 115 volt Lithium Battery is air cooled
Summary
Unlike the BAS system this one will bite. The voltage
levels are lethal and a special tool will be required to
remove and replace the drive belt. Other than a proper
scan tool, this hybrid should be one of the easier ones
to service. Time will tell.
The Buick system is very compact
82
www.fixhybrid.com • 800-939-7909