Fiat's New Diesel Engines Perform Sluggishly

Fiat has something of a pedigree where diesel cars are concerned and now, after a considerable period of silence on its diesel developments, Fiat is introducing two new modular 1910cc turbodiesel engines for use in its compact class Bravo and Brava cars. These engines are a non-intercooled low-boost 55 kW unit and an inter-cooled 73 kW engine, but a larger 5-cylinder version of this modular engine family, good for an output of 92 kW, will be appearing later in the forthcoming Fiat Marea.

Surprisingly, neither of the Bravo and Brava's new diesel engines is of the fuel-efficient direct-injection type, which most diesel engine manufacturers are concentrating on today. The reason for this may be the comparatively poor response to the previous, noisy direct-injection engined Croma.

Considering the long period of diesel silence from Fiat, some new technology could be expected, but this is not the case. Implanted in the bigger Brava models, the low-boost 55 kW engine is far from stellar. In terms of cabin noise, it has a harsh, unflattering edge to its tone that would have most diesel fanatics guessing it was a particularly refined direct-injection engine, rather than an up-to-the-minute indirect one.

On paper, the Brava five-door vehicle accelerates from zero to 100 kilometers an hour in a respectable 15.5 seconds, but when you gauge that acceleration by the tried-and-trusted seat-of-pants method, it disappoints, feeling quite a bit slower than that. And despite this low power engine's use of a smaller turbocharger -- purely there to provide a 15 percent increase in low-down pulling power and to help clean exhaust emissions -- we didn't find the TD 75 to be a particularly flexible performer.

So what of the more promising 73 kW version of this engine? Unfortunately, this is also less than superb. To be perfectly fair, it is a lively unit once it has overcome its handicap of low-speed lethargy. The TD 100 is quite a cracking engine once up and running, but it does need a desperate amount of stoking into life before it becomes responsive. Generous revs and a partly slipping clutch are needed when you wish to squirt your Fiat into that gap in tightly packed traffic. This is not how it is meant to be -- diesels are supposedly all about flexibility, and not advanced planning.

Ultimately, the buzzy TD 100 motor will power the Brava from 0 to 100 kilometers in a claimed 10.8 seconds -- and on to 180 kilometers per hour where that is permitted -- all of which is highly creditable stuff. It also has good, crisp mid-range pulling power for on-the-move acceleration, and if it was not for that low-down turbo lag, we would be more than content with the overall driveability and response of the TD 100. You can knock a few tenths of a second off that 0 to 100 kilometers per hour time when the TD 100 powers the lighter three-door Bravo, but unfortunately you can't shed the frustratingly poor response.

Does it feel as promising as the 73 kW implies? To be honest, no, and if we were to have guessed the power, we would have put it at about 65 kW instead. But, to give credit where it is due, the long gearing of the Bravo and Brava in both engine guises makes these two cars very serene -- and probably very economical -- highway cruisers.

In the light of some of the tremendous diesel car achievements in recent years, a lot was expected from these new Fiat engines. Sadly, they haven't delivered the goods, and apart from the fiscal advantages, it is hard to see the point of burdening the Brava with that sadly lacking 55 kW motor.

The TD 100 engine is a far better bet, and if open-road performance and cruising ability are of greater importance than point-and-squirt response around town, the Bravo and Brava TD 100s are certainly good enough for a closer look.

Ivor Carroll is a writer for Auto Express in Britain. He contributed this article to The Moscow Times.