That Honda Cars India Limited (HCIL) has received phenomenal response to the newly-launched compact sedan, Amaze, isn’t surprising, especially for its diesel offering with the brand new 1.5 l i-DTEC engine. This was to be the company’s first diesel engine in the Indian market, and consumer expectations were sky high. With ` 2,500 cr lined up for investment in a new plant, HCIL would expect the i-DTEC engine not just to drive volumes, but help the company earn back some of the marketshare it lost for the want of a diesel engine. We take a detailed look at the new engine, and explain why it could change the company’s fortunes in the coming years.
Honda Cars India Limited’s (HCIL) decision to stay away from introducing a diesel option in the Indian market posed several questions on the consumers’ mind. From the company’s perspective, it just had one 2.2 l diesel option in Europe, and that made no business sense to be introduced. Moreover, the company makes some of the finest small petrol motors and were trying to play to their strength.
The market scenario, however, changed rapidly over the past few years globally, instigating a mass adoption of diesel across markets. In India, the demand for diesel vehicles in particular was driven by the significant difference in retail price of diesel vis-à-vis petrol, and also higher fuel efficiency that diesels offered.
Distancing itself from diesel resulted in a declining marketshare over the years as petrol prices rapidly went up. Honda found a similar situation in many European markets too and quickly sought to develop a diesel engine platform. The result was a 1.6 l i-DTEC engine, which was also one of the first technologies from the Earth Dreams portfolio to be commercially launched. For India, Honda has lowered the displacement to 1.5 l by shortening the stroke in order to take advantage of the excise duty benefits. The engine has first been launched in Amaze, a sub-four metre sedan based on the Brio hatchback.
At the Amaze launch, we interacted with Ryuji Matsukado, Chief Engineer, Department 2, Technology Development Division 2, Honda R&D Co Ltd, Automobile R&D Center, who gave us an insight into all the changes made to suit the engine to Indian conditions, and an overview of the overall i-DTEC technology.
The 1.5 l i-DTEC engine develops a peak power of 98.5 hp and offers a class-leading claimed fuel economy of 25.8 km/l. Key benefits of the engine are compactness, lightness, reduced mechanical friction and lower engine cooling system losses.
Unlike other diesel engines, an all aluminium construction has been used for the cylinder head and open deck block. Using advanced computer simulation, the block was designed to be lightweight and compact. A new high strength nitride crankshaft is designed to deliver higher strength, while lowering weight. In order to make the main journal and pin journal material thinner, high-strength surface treatment with nitride has been used. This combination reduces losses due to mechanical friction.
The piston skirt has been redesigned to be shorter and narrower and the smaller surface area makes the engine lighter. It also helps further reduce mechanical friction losses. While optimising the piston shape, the connecting rods too were lightened. Owing to the combined weight reduction achieved by the measures listed above, Honda claims a better acceleration in addition to higher fuel-efficiency. The overall reduction in mechanical friction is to such an extent that Honda claims the diesel unit to be at par with petrol engines of similar displacement on this parameter.
The common rail injection system can deliver an injection pressure of up to 1,600 bar. Coupled with solenoid injectors and finely controlled injection timing, the combustion process is more efficient than the earlier 2.2 l i-DTEC unit. The cooling system too has been modified to offer better cooling despite a smaller size. Owing to a specially designed circulation route, water requirement has been reduced significantly and hence the water pump too has been made smaller. This directly translates into higher fuel-efficiency.
In order to complement the raft of engineering touches, Honda also developed new ultra low viscosity engine oil. The specially developed oil is claimed to enhance fuel-efficiency and improve engine reliability. Keeping in mind the dust content in various regions of the world, the design of the oil seal of the crankshaft has been changed.
While aluminium offers a weight benefit, it does pose some challenges in terms of sound insulation and absorption. We were told that apart from reducing mechanical friction a key measure to lower NVH was the removal of a balancer shaft. The balancer shaft is normally used in cast-iron engines to overcome the effects of sound and vibration arising from added weight and more moving parts.
At a time when consumer sentiment isn’t particularly good and fiscal measures are falling short of putting the automotive industry on a growth track, Honda couldn’t have had a better entrant than the i-DTEC. That the technology has been integrated cleverly into a compact vehicle with competitive pricing, further improves its commercial prospects. The next obvious step for the company would be to add more diesel models to its line-up. Although Honda hasn’t officially commented on the matter, Matsukado told us that the i-DTEC engine platform is flexible and scalable. This will provide the company with the option of deriving multiple versions for use in different vehicles. With that happening, Honda could very well be on track to not just regain its lost marketshare but gain new ground.
Text: Arpit Mahendra
Photo: Bharat Bhushan Upadhyay