Wolfsburg, Germany— Volkswagen’s compact new turbodiesel engine is a gymnastics routine and a thousand science fair projects wrapped into some gorgeous aluminum castings. Called the EA288 by the men in tight-fitting, dull-colored suits who swarm this factory town, it shows just how far VW will go to meet emissions regulations in the United States and Canada in order to keep its sales leadership among diesel-powered cars.
While having seen two conflicting sets of sales figures, we understand the point: no other automaker comes close to providing as many diesels in the lands of the Stars and Stripes and the Maple Leaf.
The VW diesel cult, which originated with the woefully slow 1976 Golf, demands its due. So the powertrain group led by Cambridge-educated Johannes Arning did the splits and then split the differences in order to meet the government’s latest strictures on emissions. They faced a 2015 model year deadline to comply with ULEV125 LEVIII ratings, which are tough on the non-methane organic gases that are precursors of ozone and the oxides of nitrogen that prove so stubbornly persistent among waste gases.
“Obviously, the whole combustion process was designed new,” Arning said in a seminar for reporters. The 1968cc engine has a bore and stroke of 81.0 x 95.5mm and a compression ratio of 16.2:1. Output is 150 hp at 3500 rpm and 236 lb-ft of torque between 1750 and 3000 rpm. While it has not yet been certified by the EPA, look for a 2- to 4-mpg increase over the 2014 Golf TDI’s rating of 30/42 mpg.
“We know what we’re expecting,” Arning said.
More efficient, more refinedThe engineers’ principal objective was to reduce cold-start emissions while improving efficiency. Technical development leader Thorsten Duesterdiek said it meant “putting a lot of money, a lot of effort in fulfilling the first forty, fifty seconds” of the emissions test.
Duesterdiek seemed remarkably bright and upbeat after the ordeal, and he continued, “The most effective way is to put precious metals into the catalyst.”
Besides a surfeit of palladium in the converter, a few other measures were taken in refining the new TDI engine. VW will make about 2.5 million of them per year, the supply coming from plants in Hungary, Poland, and Germany for the group’s 21 assembly facilities around the world. In order to achieve the highest efficiencies of scale, the TDI engine must fit into both the smallest and largest vehicles.
The improved EA288 version features reduced friction inside the cylinders; an oil pump with scrupulously controlled internal airflow; and a more compact head, thanks to a roller cam. To save energy, the water pump is as sensitive and variable as a peacekeeping force. And the engine’s thermal management system operates with three circuits governing cylinder head temperature, exhaust gas recirculation, and intake charge. The intercooler (integrated into the intake manifold) and the EGR unit (with its own heat exchanger) are designed for reduced pressure losses and improved responsiveness.
Just as VW has modular chassis architecture spreading through its car lineup, the EA288 is also modular. For example, the exhaust aftertreatment, which injects urea into the stream of waste gases to neutralize pollutants, can be tailored to suit the market. For example, Romania’s emissions standards are far less NOx-crunching than Oregon’s.
Meanwhile, the EA288 must have a taste for low-sulphur fuel while also finding B20 biodiesel to be agreeable.
A Golf SportWagen will return with the dieselThe EA288 will first be slid between the knees of the 2015 Volkswagen Golf when it appears this summer. Next it will go into the Jetta, Beetle, and Passat. The Golf SportWagen will return to the U.S. during calendar year 2015, also available with the diesel.
We expect the EA288 will not only meet its developers’ targets for lower emissions and costs but also drivers’ desires for increased performance and comfort. We can’t wait to test it for ourselves.
In the interim, we have to settle for being highly impressed with the willingness of Arning’s team to meet targets that would have seemed impossible when the 1993 Jetta TDI went on sale. The American turbodiesel cult started then, and its growth is the amazing story of a special bond between a savvy manufacturer and its enthusiastic customers.