Saturday, March 24, 2007

good motoring
It’s the golden age of diesel engines
H.Kishie Singh

Common Rail Direct Injection (CRDI) is a word that is going to be a part of your vocabulary. Its been around about a couple of years and refers to the state-of-the-art technology for diesel engines. Up to now diesel engines were noisy, sluggish and most people thought it infra-dig to drive a car with a diesel engine. It was good for taxi drivers, tractors and other commercial vehicles but not for passenger vehicles. That is about to change with this invention and it may be that the golden age of diesel is dawning more than a century after Rudolf Diesel gave the world the diesel fired internal combustion engine.

CRDI is the most advanced diesel technologies that combines fuel economy, which was why diesel was the preferred choice. Performance was the exclusive preserve of petrol engines.

Previously, the diesel fuel was injected into the cylinders via a pump and four different fuel lines. CRDI involves injecting the fuel via a “rail”, under pressure directly into the engine. This further improves efficiency and most important reduces vibration and the “clatter” that was a diesel engines’ trademark.

The “rail”—-the pipe delivering the diesel—-is connected to the injectors and introduces the diesel in two squirts. The extremely high pressure of 1,300 bars makes sure that the diesel vaporises almost entirely, mixes easily with air and burns completely. Electronic sensors make this possible. The complete combustion means no unburnt fuel and consequently no exhaust pollution. CRDi engines are Euro III compliant.

CRDI engines claim fuel efficiency of 30% over the previous engines. The Ford Fiesta with the Duratorque engine claims 24 km per litre. The acceleration is better. With the Hyundai Viva and Verna CRDI engines, the pick-up of the diesel engines is better than the petrol engines. Says Hyundai: “It is fast, quiet and economical, while maintaining the diesel engine characteristics of higher pulling power”.

While driving the Hyundai Verna on a recent test drive, it was hard to believe one was not behind the wheel of a petrol engine car. The noise, vibration, harshness (N.V.H.) was absent and wonder of wonders, the acceleration was better than the petrol engines.

With increased cabin comfort, lack of N.V.H. and fuel efficiency, a CRDI engine car will be a boon to taxi drivers and fleet operators. Their profits will definitely go up. However, this may not apply to the city-based office-goer who has a home-to-office- and-back-routine and short-hop trips. In this case a petrol engine car or a Wagon ‘R’ Duo type of combination of LPG and petrol may be more fuel efficient.

The immediate downside of a CRDI engine is that it is more expensive. In the long run spares and labour will be more expensive.

Credit for this invention goes to Fiat who did all the R+D necessary. Today the invention is being used by most diesel engine manufacturers. Mahindra and Mahindra is getting its technology from Delphi. So have the Tatas. Almost all Hyundai diesel engines are CRDI; so is the Toyota Inova and Skoda Octavia. Mercedes of course has refined the technology but the diesel engine Mercedes is no longer the only car as a taxi favourite. Even corporates are opting for this engine. The new diesel engine Swift boasts of a super silent, low maintenance Double Over Head Cam (DOHC), 1.3 litre DDIS engine. It is turbo-charged with intercooler and it comes as no surprise that it is a Fiat derived engine.

Hyundai’s luxury sedan, the Sonata, has also been introduced with a CRDI engine.

By 2010 it is estimated that CRDI engines will account for a majority of diesel engines being manufactured around the world. Yes! The golden age of diesel engines has dawned.

Happy motoring.