Dive into the heart of our 1.5TD
An Interview with Håkan Sandquist
Taking a look at Geely’s newest engine family, we talk to Dr. Håkan Sandquist, Geely’s
Director of Powertrain Strategy at CEVT China Euro Vehicle Technology.
In 2010, after Volvo joined Geely, the two saw the future trend in the automotive industry
where sustainability would be key. Emission regulations and rising fuel costs would result
in demand for more efficient engines and a transition to electrification. To meet this
demand Volvo, with Geely’s support, developed its latest VEA – Volvo Engine
Architecture, a new modular engine architecture for three and four cylinder engines
developed from the onset to support electrified powertrain systems. Developed with
sustainability in mind, the 1.5TD has the potential to meet even the most stringent future
Euro 7 emissions and global fleet CO2 targets past 2030.
Why the move towards lower displacement engines?
The move towards lower displacement smaller engines came naturally as they’re more
efficient and with modern engine technology provide the same power as larger engines.
For compact models, a three cylinder is perfect for a variety of reasons. The smaller size
leaves room for hybrid systems and gives designers more freedom. The lighter weight
improves fuel economy and makes it easier to achieve a 50:50 chassis weight balance in
front wheel drive models improving drive performance.
How did Geely and Volvo address consumer concerns over three cylinder
engines?
The main concern consumers have with odd numbered cylinder engines is perceivable
engine vibration. However, Geely and Volvo did not think this was an unsolvable
problem. For years, Volvo has utilized a five cylinder engine and has extensive
experience developing engines for the premium market segment.
The latest engine technologies in the Geely 1.5TD engine such as counterweighted
crankshafts, dual mass flywheel with centrifugal pendulum absorber damper, single
balancing shaft, low noise timing belt, high stiffness oil pan, asymmetric oil pump
impeller, engine compartment vibration dampener, etc have effectively eliminated
perceivable engine vibrations by driver and passenger inside the vehicle. NVH (noise,
vibration and harshness) in models utilizing Geely 1.5TD engine is on par or better than
some equipped with four cylinder engines.
With support of electrified systems, perceivable vibrations can be reduced even further.
Most vibration is felt during the engine start-up period and at lower engine speeds.
However with addition of hybrid electric systems, engine start-up can made near
instantaneous and low-speeds drive can be assisted by the electric motor.
Don’t smaller engines mean less power?
Powertrain technology today is very mature. Today’s state-of-the-art technologies such
as low-inertia turbochargers, superchargers, continuous variable valve timing, direct
injection, intelligent engine heat management systems, low-friction camshafts, electric
power assist, etc have made it possible to offer low displacement engines that provide
similar power to V6s.
All VEA engines are designed to accommodate a variable combination of turbochargers,
superchargers, and electric systems, which allow Volvo and Geely to offer consumers
different levels of power output within the same engine family.
In the process of developing our new engine family, we looked at the leaders in the
industry for state-of-the-art technology and benchmarked against them. Based on the
VEA, we developed engines with the best balance in performance, fuel efficiency,
refinement and cost.
With the 1.5TD, we set out to create a highly responsive, compact and powerful
premium-quality three-cylinder engine. With its low inertia turbocharger, traditional turbo
lag is minimalized and nearly unperceivable while giving the engine the endurance it
needs at higher speeds. The 1.5TD provides smooth linear power output similar to much
larger displacement naturally aspirated engines.
Where was the 1.5TD engine developed and where are they produced?
The 1.5TD was jointly developed by Geely and Volvo at Volvo R&D centre in
Gothenburg, CEVT China Euro Vehicle Technology in Gothenburg, and Geely Research
Institute in China. The VEA – Volvo Engine Architecture developed by Volvo under Geely
form the foundation the 1.5TD.
Volvo and Geely tested and validated the 1.5TD above and beyond the industry
standard. The 1.5TD engines are designed to last 15 years or 350,000 km, much higher
than the industry standard 10 years or 200,000 km.
The 1.5TD engines are produced in powertrain plants around the world following Volvo
Global Manufacturing System. The engines share over 90% of the same global suppliers
through Geely global joint procurement system.
What does it mean when Geely and Volvo say the 1.5TD was developed specifically
to support electrification?
Both Geely and Volvo are convinced that electrification is the future and Volvo has
promised that every model it sells will come with an electrified option. While the future is
electric, the present is still very much powered by internal combustion.
We’re in a transition period in which different levels of electrification is needed in different
markets. Having predicted this outcome when the idea of VEA was conceived, all VEA
engines are designed to support electrification. As a modular engine architecture, VEA
engines are essentially design with plug and play support for electrified systems. The
1.5TD have native support for MHEV, REV, HEV, and PHEV powertrains.
Geely and Volvo have so far developed three base variants of the three cylinder engine.
Additional tuning has also been made to meet the localized needs of different markets.
The three cylinder engines are all turbocharged and include port fuel injection (PFI) or
direct injection (DI). The latest variant, 1.5T Miller has been designed specifically for HEV
application by adjusting variable valve timing to enable the engine to run on the fuel
efficient miller cycle.
How do electrified systems help reduce or eliminate the shortcomings of the three
cylinder design?
Electric systems enhance the advantages of low displacement engines. Even the most
basic 48V BSG mild hybrid can improve fuel efficiency by 15% in an already efficient
three cylinder engine. Electric power offer assistance in low speed drive and engine start-
up where vibration is most commonly felt. Electric motors also add instant torque and
power which is useful for low-speed drive.
Dr. Håkan Sandquist is the Director of Powertrain Strategy at CEVT China Euro Vehicle
Technology. He has spent over 20 years researching and developing powertrain
technologies for Volvo, Geely, and other engineering firms. Dr. Sandquist received his
Ph.D in Internal Combustion Engines at Chalmers University of Technology in 2001 and
has been working with powertrain electrification for more than 10 years.
