Friday, January 24, 2014

2015 Volkswagen Golf TDI Diesel

More refined, efficient, and engaging than ever.

Whether or not it’s true that the left brain dominates rational cogitation while the right hemisphere seeds artistic ideation, we think the entirety of your noggin will be engaged by driving Volkswagen’s 2015 Golf TDI. Because after an all-too-brief session piloting a Euro-market 2014 model that’s similar to what’s coming to the U.S. for 2015, we’re sure the new diesel Golf will appeal to driving enthusiasts and fuel savers alike.

The goodness starts with the body structure and chassis of the all-new seventh-gen Golf, which already is on sale elsewhere around the globe and hits these shores the middle of next year as a 2015 model. Although more generous in cargo space, shoulder room, and rear-seat legroom than the previous-gen Golf, the longer, lower, wider 2015 has less mass to haul around. Added to continual refinements to the strut-front, multilink-rear suspension is a standard, brake-based XDS cross differential lock that enables wheelspin-free launches from rest and pseudo torque vectoring when under way. Once rolling, the Golf TDI’s ride quality is supple, yet wheel control is so outstanding that we kept hunting for more roads on which to exercise the balanced chassis.

Driven by the need to improve fuel economy, VW switches the new Golf from hydraulic to electric power steering, losing a small amount of tire feedback but retaining the precision, off-center linearity, and low friction we’ve come to expect of our repeat 10Best winner. The Euro-market Golf TDI we drove was shod with summer-only 225/45-17 Dunlop Sport Maxx RT rubber, meats unlikely to be fitted on U.S.-bound TDIs (hey, at least we know they fit). Although the Euro tires take some of the credit for the extra stick, the new TDI’s brakes are noteworthy for confidence-building top-of-pedal response, ease of modulation, and overall bite.

2015 Golf was also equipped with an electric parking brake, which frees up a lot of space on the console previously hogged by the hand-brake lever. Speaking of interior space, the Euro-spec Golf adds stash room with a handy coin box to the left of the steering column and a hidden storage nook at the bottom of the center stack. The car’s added width stretched the dash a bit, too, allowing for a slightly bigger infotainment touch screen.

VW’s been at the diesel game longer than many other manufacturers, and this Golf benefits from an all-new four-cylinder oil burner. Although the base Golf TDI doesn’t have the 184 horses and 280 lb-ft of the not-yet-but-almost-definitely-confirmed-for-the-U.S. GTD, the EA288 2.0-liter turbo-diesel is creamy and torque-rich. Windows up, the quiet cabin gives little reason to suspect there’s a diesel under the hood. Torque stays the same as that of the previous Golf TDI’s 236 lb-ft, but peak horsepower gets nudged from 140 to 150 and arrives 500 rpm lower in the rev range. This translates to a right-brain-pleasing well of low-end torque and good accelerator-pedal response. The EA288 diesel family has an integrated exhaust manifold designed to give quick warm-ups, and a urea-based after-treatment system scrubs exhaust gases. Unlike its main compact diesel competitor, the Chevy Cruze, the Golf TDI is available with a manual transmission. Compared with the shifter in the previous-gen Golf, the new, shorter-stir stick has improved feel and is even more buttery and precise than before.

I am betting that the combination of lower weight, six-speed transmissions, and new engine will result in improved EPA fuel-economy estimates versus the outgoing car’s 30/42 splits. Will the 2015 Golf TDI top the 2014 Cruze’s 46-mpg highway rating? Perhaps not, but based on our time behind the wheel, we think the 2015 Golf TDI will tickle the fancy of hypermilers and hot-hatch lovers alike.

VW’s New 2.0-Liter EA288 Four-Cylinder TDI Diesel

The EA288 diesel will be the TDI powerplant in the next-generation Golf, Jetta, and Passat. The inline configuration, iron block and aluminum head, and DOHC configuration will carry over, but horsepower from the 2.0-liter surges to from 140 to 190, while torque is up from 236 lb-ft to 280 lb-ft. Those two figures represent increases of 36 and 19 percent, respectively. Also, as with the EA211 gas engines, a belt that never requires replacement drives the camshafts.

The Canadian market was lucky enough to get an electric secondary cabin heater that kicked in when maximum heat was requested.
To remedy such heating concerns with the EA288, engineers integrated the exhaust manifold into the engine head, as they did with the EA211 gas engine. The EA288 head has its own cooling circuit controlled with valves. When the engine is cold, the head circuit is the most active, which allows the engine coolant to heat up swiftly, making it possible to warm the cabin faster. This also helps the engine get up to operating temperature more quickly, thus improving fuel efficiency.
Currently, VW diesels use a NOx storage catalytic converter in the exhaust to meet emissions requirements. To further clean up the new 2.0-liter EA288’s act—and comply with the stringent EU6 regulations—VW has employed a urea NOx reduction device, otherwise known as a selective catalytic reduction system. The combination of the urea system, two exhaust-gas recirculation devices, a particulate filter, and an oxidation catalytic converter results, says VW, in a 45-percent reduction in total emissions versus the old engine.
A pair of counter-rotating balance shafts help smooth out the power delivery and lower NVH; this feature is absent from smaller-displacement versions.

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