Audi A5 Sportback g-tron: very first drive of natural-gas luxury sport sedan
Audi’s vision of future mobility primarily centers around an array of long-range electrified cars scheduled to debut in the coming years under the “e-tron” badge.
These are intended to be Tesla killers, as they’re often called in Germany.
But there’s another kind of tron with a “made in Germany” label as well, and it’s not a robot from a 1990s science fiction movie: Audi’s g-tron cars run on compressed natural gas (CNG) as well as gasoline; running on natural gas emits less carbon dioxide per mile.
The second-generation A5 Sportback recently joined the A4 Avant wagon and the A3 in Audi’s CNG-powered family. It’s not coming to the United States, but we couldn’t fight back the chance to take one for a quick spin in Germany.
Different kind of hybrid
The A5 g-tron has a turbocharged Two.0-liter 4-cylinder engine modified to run on CNG, with engine-management software from Bosch.
It’s tuned to produce one hundred seventy horsepower inbetween Four,450 and 6,000 rpm and one hundred ninety nine pound-feet of torque over a broad band from 1,650 to Four,400 rpm.
2017 Audi A5 Sportback g-tron (European model), driven, Aug two thousand seventeen [photo: Ronan Glon]
2017 Audi A5 Sportback g-tron (European model), driven, Aug two thousand seventeen [photo: Ronan Glon]
2017 Audi A5 Sportback g-tron (European model), driven, Aug two thousand seventeen [photo: Ronan Glon]
The turbo-4 is down on power compared to its gasoline counterpart, whose ratings check in at one hundred ninety hp and two hundred thirty six lb-ft. An Audi spokesperson told us the compression ratio has been enlargened for part-load operation, which they predict will be the most common operating mode.
The TFSI engine powers the front wheels only; there’s no such thing as a g-tron quattro. A 6-speed manual transmission comes standard, but our test was fitted with the optional “S-tronic” 7-speed dual-clutch automatic transmission.
In this configuration, the A5 accelerates from zero to sixty two mph in 8.Four seconds and keeps going until one hundred forty mph. It’s about a 2nd slower to freeway speeds than the standard Sportback, yet it’s about half a 2nd quicker than the base gasoline- and diesel-powered variants.
The CNG is stored in high-pressure tanks sandwiched under the passenger compartment. They’re made of such composite materials as carbon fiber and fiberglass to avoid adding too much weight to the car.
They store a total of almost forty two pounds of gas at a pressure of two hundred bars (Two,900 psi), which provides the A5 with up to five hundred miles of driving range on CNG alone. Switching to gasoline adds another two hundred eighty miles of range, according to Audi.
Theoretically, you could drive the g-tron from Fresh York City to the outskirts of Chicago without needing to stop for fuel.
2017 Audi A5 Sportback g-tron (European model), driven, Aug two thousand seventeen [photo: Ronan Glon]
CNG is compressed methane stored under pressure. It’s relatively common in nations like Iran, Pakistan, Brazil, and Thailand. In Europe and North America, the CNG fueling infrastructure remains lil’.
When you do manage to find a station, refueling takes about as long as it would for a tank of gasoline. Natural gas is often cheaper than gasoline, too, not to mention lowering CO2 emissions.
CNG is not to be confused with liquid petroleum gas (LPG), a combination of propane and butane that’s liquefied—hence its name—and stored under pressure. LPG can’t be considered a mainstream fuel either, tho’ it has a petite but loyal following in Europe.
The g-tron is also capable of running on the “e-gas” fuel Audi manufactures in-house. It’s a synthetic natural gas produced in England and Germany since 2013. Using renewable wind energy, Audi splits water into oxygen, which is released back in the air, and hydrogen, which is retained.
The hydrogen reacts with CO2 extracted from the atmosphere to form methane, which is then routed into the European gas grid. Any CNG-powered machine, from our test A5 through the Napa Valley Wine Train to a stove on a sailboat, can run on Audi’s e-gas.
The g-tron looks exactly like a garden-variety A5, with the exception of a petite emblem at the bottom right side of the trunk lid.
There’s no extra fuel door to showcase it’s capable of moving without searing gasoline, nor does it have slabs of shiny blue trim to announce it goes effortless on the ozone layer. “Make it low-key” was the order to designers.