Honda was hugely late to market with its first effort at a diesel, the 2.2 i-CTDi, but at least when it did appear, it was one of the finest on the market.

Now, after years of inactivity on the DERV front, it is aiming to be a leader in the development of diesel by producing a Euro V-compliant engine more than a year before EU regulations make it compulsory.

Called the i-DTEC, the engine will first be fitted to the new Accord which will be launched next summer.

However, we’ve driven it in a current Accord.

Honda engineers believe their 2.2-litre i-DTEC will be one of the cleanest diesels on the market and will have a significant power upgrade over the current 140bhp.

According to Kenichi Nagahiro, chief designer and inventor of both the VTEC and i-CTDi engines, the i-DTEC will offer two states of tune, one of around 155bhp and one of 180bhp, while his goal is to eventually build diesel engines that are as clean as petrol engines for particulate matter and NOx.

The i-DTEC is still based on the aluminium unit in the i-CTDi but reaches Euro V standards through the use of the very latest engine technology.

It has the latest fuel injection technology for a shorter injection time and optimised combustion chamber shape to reduce NOx and smoke generation, a particulate filter and NOx reducing catalyst.

We drove the car around the oval track at Twin Ring Motegi in Japan, and immediately noticeable was the extra punch available over the current unit.

The current Accord is lighter than the new model due next year, but the engine – engineers would not reveal its state of tune – had much more top-end power while feeling smooth and at motorway cruising speeds was virtually silent.

Bearing in mind the number of times this engine must have been lifted in and out of the test mule, it bodes very well for the next generation Accord.

Euro V story

The Euro V standard will apply from September 2009 for new models and in January 2011 for new cars.

Pollutant emissions such as nitrogen oxides (NOx) and particulate matter (PM) from diesel vehicles can be as much as four to five times higher than petrol.

The new directive aims to close that gap, by reducing PM from diesel cars by 80% compared to Euro IV.

NOx emissions are not so strict, and have to be cut from 250mg/km to 180mg/km – against the current petrol limits (70mg/km).

The Government has not said yet that it will introduce a tax incentive for drivers switching to Euro V as it did with Euro IV.