The Audi A3 Sportback (8V) G-tron 1.4 TFSI CNG, produced from 2014 to 2016, represents a unique offering within the broader A3 Sportback (8V) generation. Positioned as an alternative fuel vehicle, it combined a turbocharged gasoline engine with the capability to run on Compressed Natural Gas (CNG), appealing to environmentally conscious buyers and those seeking to reduce fuel costs. This variant aimed to bridge the gap between traditional gasoline vehicles and fully electric options, offering a bi-fuel solution within the popular A3 hatchback body style. It was primarily marketed in European countries with established CNG infrastructure.
Technical Specifications
| Brand | Audi |
| Model | A3 |
| Generation | A3 Sportback (8V) |
| Type (Engine) | G-tron 1.4 TFSI CNG (110 Hp) |
| Start of production | 2014 |
| End of production | 2016 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (economy) – urban (NEDC) | 6.9 l/100 km (34.1 US mpg, 40.9 UK mpg, 14.5 km/l) |
| Fuel consumption (economy) – urban (CNG) (NEDC) | 4.4 kg/100 km |
| Fuel consumption (economy) – extra urban (NEDC) | 4.3 l/100 km (54.7 US mpg, 65.7 UK mpg, 23.3 km/l) |
| Fuel consumption (economy) – extra urban (CNG) (NEDC) | 2.8 kg/100 km |
| Fuel consumption (economy) – combined (NEDC) | 5.2 l/100 km (45.2 US mpg, 54.3 UK mpg, 19.2 km/l) |
| Fuel consumption (economy) – combined (CNG) (NEDC) | 3.4 kg/100 km |
| CO2 emissions (NEDC) | 121 g/km |
| CO2 emissions (CNG) (NEDC) | 92 g/km |
| Fuel Type | Petrol / CNG |
| Acceleration 0 – 100 km/h | 10.8 sec |
| Acceleration 0 – 62 mph | 10.8 sec |
| Acceleration 0 – 60 mph | 10.3 sec |
| Maximum speed | 197 km/h (122.41 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 11.5 kg/Hp, 87.3 Hp/tonne |
| Weight-to-torque ratio | 6.3 kg/Nm, 158.7 Nm/tonne |
| Power | 110 Hp @ 4800-6000 rpm |
| Power per litre | 78.9 Hp/l |
| Torque | 200 Nm @ 1500-3500 rpm (147.51 lb.-ft. @ 1500-3500 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | CPWA |
| Engine displacement | 1395 cm3 (85.13 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 74.5 mm (2.93 in.) |
| Piston Stroke | 80 mm (3.15 in.) |
| Compression ratio | 10.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 4 l (4.23 US qt | 3.52 UK qt) |
| Kerb Weight | 1260 kg (2777.82 lbs.) |
| Max. weight | 1800 kg (3968.32 lbs.) |
| Max load | 540 kg (1190.5 lbs.) |
| Trunk (boot) space – minimum | 280 l (9.89 cu. ft.) |
| Trunk (boot) space – maximum | 1120 l (39.55 cu. ft.) |
| Fuel tank capacity | 50 l (13.21 US gal | 11 UK gal) |
| CNG cylinder capacity | 14.40 kg |
| Permitted trailer load with brakes (8%) | 1500 kg (3306.93 lbs.) |
| Permitted trailer load with brakes (12%) | 660 kg (1455.05 lbs.) |
| Length | 4310 mm (169.69 in.) |
| Width | 1785 mm (70.28 in.) |
| Width including mirrors | 1966 mm (77.4 in.) |
| Height | 1425 mm (56.1 in.) |
| Wheelbase | 2636 mm (103.78 in.) |
| Front track | 1535 mm (60.43 in.) |
| Rear (Back) track | 1506 mm (59.29 in.) |
| Front overhang | 869 mm (34.21 in.) |
| Rear overhang | 805 mm (31.69 in.) |
| Drag coefficient (Cd) | 0.31 |
| Minimum turning circle (turning diameter) | 10.9 m (35.76 ft.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the front wheels of the vehicle. |
| Drive wheel | Front wheel drive |
| Number of gears and type of gearbox | 6 gears, manual transmission |
| Front suspension | Independent type McPherson |
| Rear suspension | Torsion |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 205/55 R16 |
| Wheel rims size | 6.5J x 16 |
Powertrain & Engine Architecture
The heart of the A3 Sportback G-tron is the CPWA engine code, a 1.4-liter turbocharged inline-four cylinder gasoline engine. This engine utilizes direct fuel injection and an intercooled turbocharger to deliver 110 horsepower between 4800 and 6000 rpm, and 200 Nm (147.51 lb.-ft.) of torque from 1500 to 3500 rpm. The key difference lies in its bi-fuel capability. The engine is designed to run on either gasoline or Compressed Natural Gas (CNG). When running on CNG, the engine management system automatically adjusts to optimize combustion for the alternative fuel. The G-tron system incorporates a high-pressure CNG tank, typically located in place of the spare wheel, and a fuel selector switch allowing the driver to choose between gasoline and CNG operation. The 6-speed manual transmission was standard, providing a balance between fuel efficiency and driver engagement.
Driving Characteristics
The 1.4 TFSI CNG with a manual transmission delivers a driving experience focused on efficiency rather than outright performance. Acceleration from 0 to 100 km/h (0-62 mph) takes approximately 10.8 seconds. While not particularly quick, the engine provides adequate power for everyday driving situations. The torque curve is relatively flat, offering usable power across a wide range of engine speeds. Switching to CNG slightly reduces power output compared to gasoline operation, but the lower fuel costs often offset this minor performance difference. The manual gearbox allows for precise control, but the gear ratios are tuned for economy, meaning frequent shifting may be required during spirited driving. Compared to the more powerful 1.8 TFSI or 2.0 TFSI variants, the G-tron prioritizes fuel efficiency and lower emissions over dynamic performance.
Equipment & Trim Levels
The A3 Sportback G-tron typically came with a standard equipment level similar to the mid-range A3 trims. This included features like air conditioning, a multi-function steering wheel, an infotainment system with a color display, and electric windows. Interior upholstery was generally cloth, with options for leather upgrades. Specific G-tron badging distinguished it from other A3 models. Optional extras included features like parking sensors, a panoramic sunroof, and upgraded audio systems. The focus was on providing a well-equipped and comfortable hatchback experience, with the added benefit of alternative fuel capability.
Chassis & Braking
The A3 Sportback G-tron utilized a standard A3 chassis setup. Front suspension consisted of independent McPherson struts, while the rear employed a torsion beam axle. This configuration provided a good balance between ride comfort and handling. The braking system featured ventilated discs on the front wheels and solid discs on the rear. ABS (Anti-lock Braking System) was standard. The added weight of the CNG tank, located under the floor, slightly altered the weight distribution compared to gasoline-only A3 models, but the impact on handling was minimal.
Market Reception & Comparison
The A3 Sportback G-tron was generally well-received by critics, particularly in markets with established CNG infrastructure. It was praised for its fuel efficiency and reduced emissions. However, the limited availability of CNG refueling stations in some regions hindered its wider adoption. Compared to the gasoline-powered A3 variants, the G-tron offered lower running costs but slightly reduced performance. The 1.8 TFSI offered more power and a more engaging driving experience, while the 1.6 TDI diesel provided even better fuel economy. The G-tron occupied a niche position, appealing to buyers specifically seeking an alternative fuel vehicle.
Legacy
The Audi A3 Sportback G-tron represents an early step in Audi’s exploration of alternative fuel technologies. While CNG never achieved widespread popularity in many markets, the G-tron demonstrated Audi’s commitment to reducing emissions and offering sustainable mobility solutions. Today, these vehicles can be found on the used car market, often appealing to buyers seeking a unique and environmentally friendly hatchback. The 1.4 TFSI engine itself proved to be relatively reliable, although the CNG system requires periodic inspection and maintenance to ensure safe and efficient operation. The G-tron serves as a precursor to Audi’s later plug-in hybrid and fully electric models.
