VW EA189 TDI engines offer improvements in efficiency and serviceability
Volkswagen is enjoying tremendous success with the first two generations of its EA189 four-cylinder diesel engine, which Parts & People tested in the 2012 Audi A3 TDI and 2012 Volkswagen Passat TDI, respectively.
Doug Skorupski, technical strategy manager for Volkswagen of America, said TDI engines currently constitute more than 25 percent of Volkswagen’s new-vehicle sales mix.
“If we had the production capabilities, that number could easily be north of 30 percent,” he said, noting that VW has plans to open a powertrain plant in Mexico in early 2013.
The EA189 made its debut in the North American marketplace in model year 2009, seeing use initially in the Volkswagen Jetta, Golf, and Beetle, as well as the Audi A3 TDI.
The first-generation engine did not use modern urea-injection technology, Skorupski said, but rather met its emissions standards with NOX catalysts.
With the introduction of the 2012 Passat comes the second generation of the EA189, which does include Selective Catalytic Reduction (SCR) technology.
The SCR advancement comes by way of a diesel exhaust fluid injection system, which injects a urea solution into the exhaust stream. The fluid is replaced at 10,000-mile intervals, Skorupski said.
Additionally, the second-generation engine has seen changes to its turbocharger, intercoolers, plumbing, and packaging.
“If you drive the Jetta and the Passat back-to-back, you can actually feel the Passat’s gen-2 engine as being more responsive,” Skorupski said, noting that the new, smaller turbocharger is still sourced from the same supplier.
Skorupski said the EA189 is designed with ease of serviceability in mind. The way the engine is configured, he said, should not require any specialized tools or equipment to work on.
Scott Dounn, service manager at Prestige Imports Audi in Lakewood, Colo., said the A3 TDI maintains a solid reliability record.
“There have been minor issues with the 3.0-L diesel from the Q7, but we have seen nothing specific or repetitive with the A3 TDI’s mechanicals,” he said.
Dounn said that at times, TDIs have experienced issues with VAG scan tools shutting off before their diagnostic protocol. That has happened to multiple dealerships, and on different scan tools, he said.
“Audi is going through a conversion from VAG to ODIS for its diagnostic system right now,” he said, noting that the new ODIS tool will use the Internet for updating, rather than CDs.
In all, both the A3 and Passat were a dream to drive, with each possessing a very different character. The A3’s taut, old-school German dynamics, for example, reminded us more of an E46 BMW 3-series than a newer-generation Audi A4.
The Passat, on the other hand, made a compelling argument to back up its 2012 North American Car of the Year status. With room for two six-foot adults in the back seat, plentiful power, and an observed 62.1 MPG on the highway, the Passat just might be the best car for long road trips we have found yet.
With noticeable improvements in efficiency, refinement, and serviceability, both generations of the Volkswagen EA189 TDI engine are a solid choice.
Skorupski said current manufacturing capacity for the EA189 is hovering right at 100 percent. With an engine this good, we can only hope that the gates for expansion will eventually open, and allow for a more widespread TDI expansion across VW and Audi’s U.S. lineup.
2012 Audi A3 TDI and 2012 VW Passat TDI
Front-engine, FWD, five-passenger, five-door hatch (A3)
Front-engine, FWD, five-passenger, four-door sedan (Passat)
Base price / As tested
1,968 cc DOHC I4 clean diesel, iron block and aluminum heads
140 HP at 4,200 RPM (A3); 140 HP at 4,000 RPM (Passat)
236 lb-ft. at 1,750-2,500 RPM (A3); 236 lb-ft. at 1,500-2,500 RPM (Passat)
Six-speed dual-clutch with electro-hydraulic control
City MPG/Highway MPG/As tested
30/42/35.5 (A3); 31/43/38.4 (Passat)
Front: McPherson struts, lower wishbones, anti-roll bar, track-stabilizing steering roll radius, aluminum subframe (A3); Strut-type, lower control arms, coil springs, telescopic shock absorbers, anti-roll bar (Passat)
Rear: Four-link independent, anti-roll bar, subframe (A3); Four-link independent, anti-roll bar, acoustically decoupled axle (Passat)
A3: Old-school, solid Germanic feel and looks with modern mechanicals.
Passat: The best blend of performance, economy, value, and comfort we have found yet.