The world’s largest maker of petrol engines, Honda, didn’t take easily to making diesels. Despite clear indications and global trends, the Japanese motorcycle and car manufacturer shied away from ‘dirty oil burners’ for years. Honda culture, you see, was all about petrol engines. Built on the bedrock of motorsport, high-revving petrol engines and driving pleasure, diesels were an anathema.
But the skyrocketing price of fuel and a loss of marketshare in certain markets has forced Honda’s hand. The new i-DTEC diesel engine is the first small capacity diesel to be launched by Honda. Known as Earth Dreams Technology, this new 1.6 engine will make its introduction at the beginning of 2013 and offers a potentially class-leading combination of 118bhp and 30.5kgm torque.
“The key focus of our Earth Dreams Technology philosophy is to balance environmental efficiency with the dynamic performance expected of a Honda,” says Suehiro Hasshi of Honda. “It is important that our cars are fun to drive.” Developing this engine has been all about smart engineering, according to Honda, who is looking to make a large overall difference from small detail improvements.
Honda’s 1.5-litre i-DTEC motor for India uses the same architecture as the 1.6 and also comes with the same sophisticated hardware to reduce weight and friction. The only differences are that the Indian version has a smaller, fixed-geometry turbo (FGT) and no Diesel Particulate Filter (DPF), which is not needed in India. The 1.5 shares its pistons with the 1.6 (the bore is the same) and hence it is only the stroke that has been reduced to bring the capacity below the critical 1.5-litre mark (to qualify as a small car engine and gain excise benefits). Honda claims this engine is the lightest diesel in its class and a host of weight-saving features have been used, like a thin-walled aluminium block, an aluminium head and lightweight cast-iron cylinder liners.
Refinement is another area where Honda engineers have worked hard, especially since the properties of an aluminium block (which transmits more noise) require significant countermeasures. Honda has stiffened the crankcase and opted for liquid-filled engine mounts to reduce vibrations.
Also of interest is the fact that the engine has been designed to accommodate a variable-geometry turbo (VGT), so you can expect a more powerful version of this engine to power the next-generation City and Jazz too. Honda will produce the engine in India, localising many of the components, and that will mean a very competitive price could be possible.
Lightest diesel in its class
Honda claims that the all-new i-DTEC diesel motor is the lightest diesel engine in its class. This feat was achieved by having all the individual components redesigned to minimise their weight and size, along with a reduction in the thickness of the cylinder walls to 8mm, which is great. The engine itself is comprised of an aluminium cylinder head joined to an open-deck aluminium block. The engine also utilises lighter pistons and connection rods to keep the weight as low as possible.
Reduced mechanical friction
Honda claims it has worked hard at reducing the mechanical friction of the i-DTEC engine. Case-in-point being the use of a shorter and thinner piston skirt, which, according to Honda, has around 40 percent less mechanical friction at 1500rpm than a conventional diesel – this will help fuel economy and smoothness.
Efficient fuel-injection system and air flow
With the use of a Bosch solenoid injection system, the i-DTEC engine is capable of operating at a pressure of 1800bar. This implies that the fuel is injected at a faster rate, along with a finer atomisation of the fuel spray. As a result, the fuel mixes more efficiently with the air, leading to a cleaner and more efficient mixture.