In just a few months, Audi’s A5 coupe will hit the market in the United States, with its more powerful S5 sibling already here. The first new Audi to be produced on the company’s B8 chassis, the coupe will be followed next fall by the next-generation A4 sedan. Those watching the latest Audi offerings with interest have probably noted a distinct lack of 4-cylinder carryover. Of course there’s the FSI 4.2-liter V8 in the S5 and the A5/A4 ranges have been confirmed to have the 3.2l V6 FSI with valvelift, but those on a budget or looking for even more efficiency in the North American range are already asking for something to slot below the 3.2. Audi knows the demand is there, with several executives having confirmed that an all-new 2.0T-FSI is on the way. That in mind, Fourtitude recently had a chance to sample prototype versions of the A5 with experimental versions of the all-new engine.
This wasn’t the typical test drive of a new model as we typically report. There wasn’t an extended drive with well-researched, driver-oriented routes or several days to spend in a car and learn its nuances. These weren’t made-for-prime-time production models, but engineering test mules built to show off new technologies. Those attending were invited to try out new, fuel-saving technologies from Volkswagen and Audi. Among them, there was an Audi A5 that ran on ethanol and another that made use of engine start-stop technology with a ‘micro-hybrid’ system using energy regeneration during braking and free wheeling for improved efficiency.
Thanks in part to the use of bio-derived fuel in the ethanol A5, the first coupe was good for 75% better CO2 emissions than a typical A5 road car. Even more applicable in daily use, the start-stop equipped A5 with its regenerative brake system is good for 40 mpg. Sources at Audi say the ethanol variant was more a show of what can be done, but hardware such as the regenerative braking and start-stop technology are more likely to see near-term production.
Short stints around downtown San Francisco were provided in order to learn the daily drivability of experimental drivetrains such as these. Such a drive isn’t optimum for learning handling dynamics, but the two A5s were far from production spec anyway. More importantly, the 2.0T motors that beat under the hoods of these coupes were from the Volkswagen Group’s latest ‘EA 888’ engine family of gasoline-powered 4-cylinders and also equipped with valvelift. Essentially, if you ignore the experimental fuels or components, the specifications of these two motors are close to what will go into full production in the A4 and A5 in the near term and should see duty eventually in transverse applications such as the A3 and TT. Non-valvelift versions of the EA 888 series 2.0T, we hear, are already being fitted to production A3s.
The EA 888 engine project was the brainchild of former Audi AG board member Wolfgang Hatz. Hatz, who has since followed Martin Winterkorn to Audi parent Volkswagen AG, has taken a post as head of drivetrains for the entire company. Given that, it’s not surprising that versions of this more efficient, refined and cost-effective engine family will see duty across all group brands from Audi and SEAT to Skoda and Volkswagen.
The first of the EA 888 series to see production was the 1.8T-FSI available in European market A5s. Changes in the 1.8T-FSI confirm many of the internal detail redesigns and upgrades that will be found in future 4-cylinder applications.
One of the most significant changes to this new family is the incorporation of a chain-based drive. Building on lessons learned in developing Audi’s 4.2l V8 for compact applications like the S4, use of inverted-tooth chains to drive camshaft, oil pump and balance shaft operation resulted in lowered noise levels and lowered frictional loss while the chain system’s useful life matches that of the engine.
Seldom seen in four-cylinder applications, EA 888 also makes use of balance shafts integrated into the lighter grey cast iron crankcase. Unlike other balance shaft designs, the new configuration from Audi combines for improved cost and lower noise, as well as optimized weight and crank case stiffness. Eight counterweights have also been used in the crankshaft for optimum internal balance.
The EA 888 family is also quite flexible. It’s suitable for production anywhere in the Volkswagen Group’s network of engine production facilities. The engine family can take a wide variation of fuel quality, allowing it to be used in any of the markets in which the Volkswagen Group sells cars. Designed to be lighter than the equivalent displacement engines they replace, the EA 888 family is also sturdy enough for applications on the liberal side of 134 hp per liter. They also boast more dynamic torque buildup that’s more pleasurable to drive and consumes less fuel in the process.
Even more components have been added to increase efficiency and lower weight. There’s a variable oil pump, twelve percent more efficient due to lowered friction and a variable volume steering pump nets similar gains. Also, fuel pressure in the production 1.8T-FSI is up to an improved 150 bar.
Planned for the higher-cost applications of the 2.0T-FSI like Audi’s A4 and A5, an even more efficient and powerful 2.0T-FSI will come equipped the company’s unique new valve control system known as valvelift. This component alone is good for five percent better fuel economy, but it also further augments torque, making turbocharged applications like our A5 2.0T mule feel like a brawny naturally aspirated V6.
Unlike other bulky and complex systems, valvelift is cleverly simple, with control directly on the camshafts that allows for lightning quick adjustment – just two turns of the crankshaft. Employment of valvelift provides the ability of the engine to dethrottle intake under partial load. By varying patterns of the two inlet valves, the charge is specifically tuned for optimized consumption and power. Where this seriously translates into fuel savings is pulling at constant speeds under partial loads – basically highway and even high-speed autobahn cruising.
Currently, Audi claims the system is stable at engine speeds reaching 7,200 rpm, suggesting a wide compatibility for valvelift applications in Volkswagen Group offerings will eventually be seen. However, valvelift is not yet compatible with high-revving mills like the 4.2-liter V8 found in the RS 4 and R8.
The most powerful of the two EA 888 2.0T-FSI A5s on hand was rated at 210 hp – likely not far from a production number and not terribly groundbreaking. Where the next-gen 2.0T really shatters the schema of the outgoing motor is torque. At 236 lb/ft, the Ethanol-powered A5 was closest to production numbers that sources have told us will be on the up side of 250 – impressive, and enough to easily rival the current 3.2 V6’s 243 lb/ft.
So how does it drive? On the streets of downtown San Francisco, torque was plentiful and came on in a linear fashion improved over the elder 2.0T. Though the buzziness of the current 2.0T isn’t gone entirely, refinement levels over the old are markedly improved.
Most Audis sold today are quattro, but both A5 mules on hand for driving were front-wheel drive ‘FrontTrak’ models – optimized for fuel efficiency. Under hard acceleration, the FrontTrak A5 spins its wheels in a manner consistent with current 2.0T front-wheel drivers equipped with higher-powered aftermarket ECUs. Though the Audi’s multi-link front suspension design admirably minimizes torque steer, getting the power to the ground remains an issue – one most enthusiasts would say is a good problem to have. With so much torque, this engine really would be better paired with Audi’s quattro all-wheel drive system.
In mainly stop-and-go traffic around downtown San Francisco, there was little-if-any chance to push the A5 into corners hard enough to get a feel of extreme handling, though we’d guess Audi executives didn’t want a significantly pricey engineering prototype sliding around San Fran streets anyway. Still, we can’t help but think that 2.0T A5s and A4s will handle quite well.
This new engine is even lighter weight than the current 2.0T. That lighter mill is wrapped in the more neutrally-handling packaging of the B8 platform, set on Audi’s new Modular Longitudinal Platform (MLP) with its engine placement lower and further back in the chassis. We’ve already sampled 3.2, 3.0 TDI and S5 versions, cars with more weight in the nose than the 2.0T though still manage to be more neutral than any B,C or D-based Audi of yore.
Due to the short test circuits, gauging real world fuel economy was also impossible. Materials provided by Audi say the Ethanol-based car, differing mainly in ECU programming from what we’ll first see, gets an estimated combined fuel consumption of 31 mpg when mated with our car’s manual 6-speed transmission. That car will also knock out a 0-60 run in 6.7 seconds with this more-frugal-than-fast programming. Interestingly, the lower reported power levels (210 hp, 207 lb/ft) of the start-stop high efficiency A5 supposedly net a faster 6.6 seconds to 60 mph and 40 mpg combined consumption.
When 2.0T-FSI versions of the A5 and A4 hit the market, they’re not expected to be touted as ethanol compatible and may or may not include components such as regenerative braking when they launch. Full production versions of both are expected in the American market sometime next fall. While big displacement versions may be both sexier and more luxurious, a growing demand for low consumption further driven by recent CAFE standard changes should make A5 and A4 2.0T models popular with buyers even before improved straight-line and cornering performance is considered.
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