The perfect increase in efficiency
8HP 8-speed automatic transmission for passenger cars
Innovation by reduction: efficiency, perfected
The new 8HP 8-speed automatic
luxury cars, and in every type of SUV and off-road
transmission, which was designed
vehicle – its revolutionary design is always an
to be more lightweight, sets new
efficient and economical solution.
standards for flexibility, efficiency, and economy. It is an excellent
Although the 8HP features 2 more speeds than the
example of how the power of inno-
extremely successful 6HP, the dimensions have
vation can create a new classic
remained unchanged and the weight was even
design.
reduced by 3 percent to 89 kg (196 lbs.) including oil.
A torque range from 300 to 1000 Nm makes the 8HP the perfect
At the same time, the total transmission ratio spread
partner for all rear-wheel-drive and
of 7.0 ensures that the engine is always in its
all-wheel-drive designs. From the
optimum operating range. This translates into
lower midsize segment to sporty
improved acceleration and reduced fuel
Weight [kg]
consumption.
5HP30 118.5 kg
120
110 6HP32 99.0 kg
5HP24 99.0 kg 100 6HP26 89.0 kg 90
5HP19 79.0 kg
6HP28 91.0 kg 8HP90 95.0 kg
6HP21 78.0 kg
8HP70 87.0 kg
80 6HP19 77.0 kg 70
200
300
8HP45 77.0 kg 400
500
600
700
800
900 Torque [Nm]
ZF Automatic Transmissions – Weight Comparison
2
Clutch
Gearset 4
Brakes
Torque converter with torsional vibration damper
Gearsets 1 to 3
Mechatronics module
Vane-type oil pump (not visible) 3
Unbeatably flexible: our modular construction system
For the 8-speed automatic transmis-
The flexible modular construction system of the 8HP
sion, ZF set out to design and
is full of innovations and is well-suited to serve as
develop an entirely new gear set
the basis for a wide range of future development
concept. The result is a revolution
possibilities. The following technologies can be
in transmission design: a transmis-
implemented without altering the transmission
sion concept with 4 gearsets which
installation space:
requires only 5 shift elements – of which only two are open in any
• Hydrodynamically cooled clutch
given gear.
• Integrated starting clutch • Crankshaft starter generator • Integrated hybrid
The 8HP also requires no more than 3 multi-disk clutches and 2 brakes, which allows it to achieve a greater
As a future-proof transmission, the 8HP is also com-
degree of efficiency than other con-
patible with the following all-wheel-drive concepts:
cepts. As a result of the fact that only 2 shift elements are open per
• All-wheel drive center differential integrated
gear, drag losses in the transmission
• Integrated all-wheel drive system (IAS©)
are sustainably reduced. This effect
• Hang-on all-wheel-drive
is supported by the use of a new parallel-axis vane-type oil pump.
A B D E
1
2
3
4
5
6
7
8
C RS1 RS2
RS3
RS4
1 2 3 4 5 6 7 8 R A Gear
B Brake
C
D Clutch
4.70 3.13 2.10 1.67 1.29 1.00 0.84 0.67 -3.30
Spread 7.05
Ratio
Gear step
1.50 1.49 1.26 1.30 1.29 1.19 1.25
E
Transmission system 4
8HP
micro hybrid + HIS©
Base transmission with torque converter
mild hybrid Torque converter possible + electric motor
Modular hybrid construction system for 8HP HIS: Hydraulic Impuls Storage (HIS©) IAE: Integrated starting element IEP: Integrated electric pump
Recuperation Boosting
Stop/Start The engine is switched off during stand-still. When starting, the electric motor automatically starts the engine again.
The electric motor assists the engine when accelerating. The additional propulsive power enables the engine to be designed in a smaller, lighter, and more fuel-saving way (downsizing).
full hybrid with electric motor
Purely electric driving Electric starting (driveoff) Additional Features For the particularly fuel-intensive starting process, it is exclusively the electric motor which provides propulsion.
The vehicle also runs for a longer distance with the power supplied only by the electric motor. The required energy is provided by the battery.
8HP (for longitudinal installation) 300-1.000 Nm, for gasoline or diesel engines
Fuel Savings* 6% 5%
with start/stop (HIS©)
15%
as a mild hybrid
25%
as a full hybrid
Vehicle classes Standard and all-wheel drives
Compact vehicle class
Mid-size class/full-size vehicle class
Luxury vehicle class
SUVs/Pickups
*Compared with the 2nd-generation 6HP 6-speed automatic transmission in the NEDC
5
Sustainable concept for the powertrains of the future
The 8-speed automatic transmission
shuts off the engine when the vehicle comes to a
reduces overall fuel consumption by
stop and immediately re-activates the engine and
at least 6 % compared to present
transmission when the footbrake is released.
state of the art 2nd Generation ZF 6-speed automatic transmissions.
The flexibility of the 8HP makes it a future-proof
As an example, the CO2 emissions
partner for even more sustainable powertrain
of a six-cylinder engine with a
concepts such as hybrid solutions. In a full-hybrid
displacement of 2.5 liters can be
vehicle, the 8HP can help to reduce fuel consump-
reduced from 180 g/km to 169 g/km.
tion by an additional 25%. The modular structure
An important contribution to this
ensures significant long-term economic advantages
reduction is provided by the
over rigidly designed driveline configurations.
increasingly popular engine start/ stop function, which automatically
–5 % –3 % –6 % –5 % –15 % bis –25 %
Example: CO2 emissions of a sedan with a 2.5 liter, 6-cylinder engine 5-speed
180g/Km
169g/Km 161g/Km
144g/Km 127g/Km
6-speed 6-speed
8-speed 8-speed
8-speed 8-speed
1. Generation 2. Generation
Start-Stop (HIS©)
Mildhybrid
Fullhybrid
ZF Automatic Transmissions – Fuel Savings 6
Innovations that deliver for partners and drivers
With its transmission innovations,
ble or sporty – every wish for individualized driving
ZF seeks to achieve many goals: to
pleasure can be satisfied. Those who appreciate
satisfy reliable partnerships, create
agility will be happy to know that the most modern
sustainable solutions for the future,
adaptive shift strategies are used which enable
and – last but not least – excite
direct skip-shifts over multiple gears, even allowing
drivers worldwide. The 8HP shifts
for extreme downshifts such as 8th gear to 2nd gear.
faster and more precisely than a
In spite of the dry facts, maximum driving pleasure
professional driver, requiring less
is guaranted.
than 100 milliseconds to initiate a downshift when increased accelera-
The automotive world has expressed its enthusiasm
tion is desired. Whether comforta-
for the flexibility, variety of applications, and future potential of the 8-speed automatic transmission. The
Since 2006 ZF has consistantly won the readers‘ choice of the German magazine „auto motor und sport“ for the transmission category.
American trade magazine ‘Automotive News’ awarded ZF the 2010 PACE Award for the engineering of the 8HP.
7
ZF Friedrichshafen AG PO Box 650464 66143 Saarbrücken Germany Phone +49 681 920-0 Fax +49 681 920-2377 www.zf.com
Driveline and Chassis Technology
