FIAT Auto appears to have done the impossible. The Italian manufacturer has produced a diesel engine that sounds and feels -Italian. And the launch of the 130bhp 2.4-litre common rail technology JTD in the Marea range couldn't have been better timed. Right now diesel is the hottest topic in fleet. The Inland Revenue's announcement that a 3% penalty is likely to be slapped on top of the benefit-in-kind charges applied to company diesel car drivers shouldn't have surprised anyone - after all, the Government had said all along that the proposed new car tax regime would be based on carbon dioxide 'and other emissions'.

The new tax system will be based on a proportion of a car's list price, ranging from 15% for the least polluting models - those with a CO2 rating of 135g/km or below - and will rise by 1% per 5g/km of CO2 emitted, to a maximum of 35% of list price. But the additional loading of 3% reflects concerns that while diesel emissions of CO2 are generally lower than those of petrol there is still the matter of harmful particulates and oxides to clear up. On top of rising diesel fuel prices, this latest knock has rattled the cages of vehicle manufacturers who have poured millions into driving oil-burners into the automotive fast lane.

Among them, the champions of common rail, Peugeot and Citroen, believe those who are composing company car tax policy for the future have failed to keep pace with diesel technology, citing their HDI engines' cleanliness and refinement compared with that of their turbodiesel predecessors and drawing attention to the development of particulates traps and pollutants filters which are expected to become standard-fit on new PSA cars by the time the new BIK rules leave the starting blocks in April 2002.

Be sure there's plenty more heat to be exchanged on the merits and demerits of diesel. Meanwhile, Fiat has come along with two high technology common rail diesels - a 1.9-litre 105bhp JTD four-cylinder and 2.4-litre 130bhp JTD five-cylinder - and a revised Marea saloon and estate range to do them justice.