Petrol engines with diesel economyMay 5, 2009
A number of manufacturers are currently working on developing petrol engines with diesel levels of economy and CO2 emissions. Now, UK company Controlled Power Technologies (CPT) has developed its own product.
The idea is that the new engine retains all the traditional cost, weight, refinement and emission benefits as well as the fun-to-drive factor of a petrol engine, while reducing CO2 levels to that of an equivalent diesel powertrain.
CPT has worked with the world’s largest independent developer of vehicle powertrains, AVL List GmbH (AVL), to produce a demonstrator vehicle with a 2-litre 4-cylinder engine with gasoline direct injection (GDI), double cam phasing and single-scroll, waste-gated turbocharger to deliver high power and torque outputs of 200PS and 400Nm respectively.
A system of cooled, external exhaust gas recirculation (EGR) and advanced thermal management further enhance the CO2 reduction potential of the powertrain.
The philosophy of ‘down-speeding’ is fully employed through the fitment of gear ratios more normally associated with turbocharged diesel engines. Successful down-speeding relies heavily on the immediate availability of high torque levels at very low engine speeds in response to driver inputs.
The integration of CPT’s variable torque enhancement system (VTES) supercharger technology virtually eliminates all perceptible turbo-lag.
Through integration of the above technologies and the implementation of engine stop-start and smart alternator control, AVL is able to demonstrate CO2 emissions of just 159g/km for a VW Passat demonstration vehicle at 1,590kg vehicle mass, which also meets Euro 5 emission standards. In comparison, a series production Passat emits 165g/km when fitted with a 2.0l TDI (170PS) diesel engine and 194g/km when fitted with a 2.0l TFSI (200PS) petrol engine.
At the same time the 200PS engine delivers high levels of performance & refinement whilst VTES ensures outstanding response even at the lowest engine speeds, equivalent to a naturally aspirated engine of twice the capacity.
“Getting a gasoline engine to deliver the lower CO2 emissions of a diesel engine is something of a holy grail for the motor industry,” says Nick Pascoe chief executive officer CPT. “The challenge is to retain the driveability at low engine speeds in order that drivers can fully realise the benefits of down-speeding. An electric supercharger can react instantly to these transient load conditions, delivering up to 25kW of additional power at the crankshaft in less than a second.”
CPT’s VTES supercharger technology benefits from almost a decade of research and continuous product development resulting in a robust and cost-effective system.
Formed two years ago as a management buy-in funded by private venture capital, Controlled Power Technologies is backed by a number of prominent investors specialising in the ‘Cleantech’ energy and environmental sectors. CPT’s core competencies include power electronics, control software and the application of electrical machines to vehicle powertrains.
The AVL demonstrator will be available for test drives at the International Vienna Motor Symposium being held on 7-8 May 2009.