ECOdiesel Review - Car and Driver


Volkswagen Jetta ECOdiesel

In a world of automotive meat-eaters, VW still offers a vegetarian.

By Don Schroeder
Photography by Jeffrey G. Russel

If you're the type that sees driving as a character-building exercise -- particularly in the disciplines of penny-pinching and self-denial -- you might want to consider trying a diesel car. Its acceleration will certainly try your patience. Finding a diesel fuel station in an unfamiliar neighborhood can also be trying. And keeping the motor running on a truly cold day can be, well, very trying indeed.

Twenty years ago, diesel fuel cost about half as much as regular gas, and that was motivation enough to encourage more than a dozen automakers to turn out diesel models. Just a decage ago, diesels sold in the hundreds of thousands and had a five-percent lock on new-car sales.

But times and attitudes and fuel prices change. Today, diesel fuel costs more than gas -- about a dime a gallon more -- although the engines that burn it do provide higher mileage: 20 to 40 percent higher than their gasoline counterparts. But few buyers see this benefit as sufficient reason to go diesel. Consequently, the number of automakers that make diesel passenger cars for American drivers is down to just two -- Mercedes-Benz and Volkswagen. For 1991, just 8805 diesel cars were purchased in this country.

We've already sampled Mercedes' civilized diesel, the 300D Turbo (C/D, September 1990), and now it's the VW Jetta ECOdiesel's turn. But wait, what's this ECO bit? Past Volkswagens made do with Dr. Diesel's undoctored name. Turns out the prefix doesn't imply an endorsement by the Sierra Club or even Ed Asner, but it does signal some fresh hardware that makes VW's engine more earth-friendly.

One of the problems with diesels is that they're stinkers, both to the nose and the environment. What you see and smell when driving behind a diesel is soot -- unburned fuel in the form of carbon particulates that most diesels produce under load. The Volkswagen ECOdiesel gives soot the old one-two punch. Punch one is a turbocharger. Its ten pounds per square inch of boost serves not only to increase power (there's only seven more horsepower than 1991's normally aspirated diesel produced) but also to channel excess air into the cylinders for more complete combustion. Punch two comes in the form of a two- way catalytic converter that burns off excess hydrocarbons and converts noxious carbon monoxide into carbon dioxide.

It's an effective smoke screen. According to Volkswagen, particulate emissions have been cut in half, and CO and HC spewings drop by 90 percent and 65 percent, respectively. Were it not for the Peterbilt din coming from under the hood, you would be hard pressed, standing curbside, to identify this as a diesel. At least until you climbed in and went for a spin.

To those used to high-revving VW gas engines, driving the ECOdiesel can be disconcerting. Diesels are governed to run at lower rpm than their gasoline counterparts, because the diesel combustion process takes a longer time to ignite the fuel in the cylinders. This engine is no exception: above 5000 rpm or so, the power drops off the cliff, just like that Beetle in the movie Sleeper. The ECOdiesel has no tachometer, so VW has added hash marks on the speedometer to indicate "suggested shift speeds" that will wring out the best of the turbo-diesel's thin 59 horsepower. Still, with 2519 pounds to carry around, the ECOdiesel's acceleration remains leisurely: 16.2 seconds to 60 mph and 20.2 seconds through the quarter-mile.

Of course, no one invests in a diesel for motives of speed. The high priority is practicality, or frugality. The Jetta's design is six years old, and its strong points have always been a decent interior layout, firm yet comfortable seats with great headroom, and a spacious trunk. The styling, though, hasn't aged as gracefully. Our base car's interior, with its plastic headliner, blocky-looking dashboard, and formless rubber shift boot, looks decidedly bargain-basement.

But what about mileage, the diesel's vaunted ace in the hole? This Jetta's 37-mpg EPA city score makes it the highest-mileage compact offered in the United States. But it's not the only low-budget fuel-sipper. Take Honda's Civic VX subcompact: though it's not as roomy, it gets even better mileage (48 mpg city), it offers an air bag, and it has real-world power in a snappier-looking package, without diesel hassles. And the base Civic VX costs $1360 less than the base ECOdiesel.

Though the Jetta ECOdiesel may wither under the harsh competitive spotlight, Volkswagen deserves praise for improving its diesel when most other manufacturers have thrown in the towel. And economy-minded drivers who couldn't care less about this ECOdiesel's dog-trot acceleration and dated looks may decide its spacious accommodations and exceptional mileage make it a grand device. There are a few of these cars left at the dealers, but a new Jetta ECOdiesel is due in 1994 -- restyled and offering more power. It may be worth the wait.

Click here for Car and Driver's ECOdiesel specifications and performance data.