The Audi A5 Sportback 40 g-tron, produced from January 2020 to 2024, represents a unique offering within the F5 generation of the A5 Sportback line. This variant distinguished itself by its bi-fuel capability, designed to run on both gasoline and Compressed Natural Gas (CNG), catering to markets with established CNG infrastructure and incentives. Positioned as a more environmentally conscious alternative within the A5 range, the 40 g-tron aimed to balance performance with reduced emissions, appealing to buyers seeking a practical and efficient grand tourer. It occupied a middle ground in the A5 Sportback lineup, offering a compromise between the base models and the higher-performance variants like the 45 TFSI.
Technical Specifications
| Brand | Audi |
| Model | A5 |
| Generation | A5 Sportback (F5, facelift 2019) |
| Type (Engine) | 40 g-tron (170 Hp) S tronic |
| Start of production | January, 2020 |
| End of production | 2024 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Fastback |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption at Low speed (WLTP) (CNG) | 6.3 kg/100 km |
| Fuel consumption at Medium speed (WLTP) (CNG) | 4.3 kg/100 km |
| Fuel consumption at high speed (WLTP) (CNG) | 3.7 kg/100 km |
| Fuel consumption at very high speed (WLTP) (CNG) | 3.9 kg/100 km |
| Combined fuel consumption (WLTP) (CNG) | 4.3 kg/100 km |
| CO2 emissions (WLTP) | 117 g/km |
| Fuel consumption (economy) – urban (CNG) (NEDC) | 5.2 kg/100 km |
| Fuel consumption (economy) – extra urban (CNG) (NEDC) | 3 kg/100 km |
| Fuel consumption (economy) – combined (CNG) (NEDC) | 3.8 kg/100 km |
| CO2 emissions (NEDC) | 104 g/km |
| Fuel Type | Petrol / CNG |
| Acceleration 0 – 100 km/h | 8.4 sec |
| Acceleration 0 – 62 mph | 8.4 sec |
| Acceleration 0 – 60 mph | 8 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Emission standard | Euro 6d-ISC-FCM |
| Weight-to-power ratio | 9.7 kg/Hp, 103 Hp/tonne |
| Weight-to-torque ratio | 6.1 kg/Nm, 163.6 Nm/tonne |
| Power | 170 Hp @ 4450-6000 rpm |
| Power per litre | 85.7 Hp/l |
| Torque | 270 Nm @ 1650-4400 rpm (199.14 lb.-ft. @ 1650-4400 rpm) |
| Engine layout | Front, Longitudinal |
| Engine displacement | 1984 cm3 (121.07 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Fuel injection system | Direct injection |
| Engine aspiration | Turbocharger, Intercooler |
| Kerb Weight | 1650 kg (3637.63 lbs) |
| Max. weight | 2130 kg (4695.85 lbs) |
| Max load | 480 kg (1058.22 lbs) |
| Trunk (boot) space – minimum | 390 l (13.77 cu. ft.) |
| Trunk (boot) space – maximum | 1200 l (42.38 cu. ft.) |
| Fuel tank capacity | 7 l (1.85 US gal | 1.54 UK gal) |
| CNG cylinder capacity | 17.3 kg |
| Max. roof load | 90 kg (198.42 lbs) |
| Permitted trailer load with brakes (8%) | 1700 kg (3747.86 lbs) |
| Permitted trailer load with brakes (12%) | 1500 kg (3306.93 lbs) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs) |
| Permitted towbar download | 80 kg (176.37 lbs) |
| Drag coefficient (Cd) | 0.27 |
| Minimum turning circle (turning diameter) | 11.7 m (38.39 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 | 7 gears, automatic transmission S tronic |
| Front suspension | Independent multi-link suspension, Transverse stabilizer |
| Rear suspension | Independent multi-link spring suspension with stabilizer |
| 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 | 225/50 R17 |
| Wheel rims size | 7.5J x 17 |
Powertrain & Engine Architecture
The heart of the A5 Sportback 40 g-tron is the 1.8-liter turbocharged four-cylinder engine, specifically the EA888 family. While the base engine code is often associated with gasoline applications, the g-tron variant incorporates significant modifications to accommodate CNG operation. The engine utilizes direct fuel injection for both gasoline and CNG, with separate injection systems and fuel tanks. The engine management system seamlessly switches between fuels, or operates on a mixture of both, depending on driving conditions and driver preference. The turbocharger and intercooler contribute to the engine’s 170 horsepower output, achieved between 4,450 and 6,000 rpm, and 270 Nm (199 lb-ft) of torque available from 1,650 to 4,400 rpm. The S tronic seven-speed dual-clutch transmission provides quick and smooth gear changes, enhancing both performance and fuel efficiency. This transmission is known for its responsiveness and ability to adapt to various driving styles.
Driving Characteristics
The 170 hp and 270 Nm of torque delivered by the 40 g-tron powertrain provide adequate performance for everyday driving. Acceleration from 0 to 62 mph (0-100 km/h) takes approximately 8.4 seconds, and the car reaches a top speed of 130 mph (210 km/h). Compared to the more powerful 45 TFSI variants, the 40 g-tron offers a more relaxed driving experience, prioritizing fuel economy and lower emissions. The S tronic transmission contributes to a seamless power delivery, and the gear ratios are optimized for both CNG and gasoline operation. When running on CNG, the engine exhibits a slightly different power characteristic, with a focus on torque at lower engine speeds. The overall driving experience is refined and comfortable, typical of the A5 Sportback, but with a noticeable emphasis on efficiency.
Equipment & Trim Levels
The A5 Sportback 40 g-tron typically came equipped with a generous level of standard features. These included Audi’s MMI infotainment system with a 7-inch touchscreen display, automatic climate control, and a suite of driver-assistance systems such as lane departure warning and automatic emergency braking. Interior upholstery was typically cloth or a combination of cloth and leatherette, with options for full leather available. Trim levels varied by market, but generally offered upgrades such as larger alloy wheels, a panoramic sunroof, and a premium sound system. The g-tron specific features included the CNG tank installation, which slightly reduced trunk space compared to gasoline-only models.
Chassis & Braking
The A5 Sportback 40 g-tron utilizes a front-wheel-drive layout with an independent multi-link suspension on both the front and rear axles. This suspension setup provides a comfortable ride and good handling characteristics. The front suspension incorporates a transverse stabilizer bar to reduce body roll during cornering. Braking duties are handled by ventilated discs at the front and solid discs at the rear, with ABS and electronic stability control as standard features. The braking system is well-modulated and provides ample stopping power for the vehicle’s weight and performance.
Market Reception & Comparison
The Audi A5 Sportback 40 g-tron was primarily targeted at markets with strong CNG infrastructure and government incentives. Critics generally praised the car’s fuel efficiency and reduced emissions, but noted that the CNG tank installation reduced trunk space. Compared to the gasoline-powered A5 variants, the 40 g-tron offered a lower purchase price in some markets due to government subsidies. However, the availability of CNG refueling stations was a significant factor for potential buyers. The 40 g-tron offered a compelling alternative to diesel-powered vehicles, providing a cleaner and more sustainable option without sacrificing the A5 Sportback’s overall refinement and practicality.
Legacy
The Audi A5 Sportback 40 g-tron represents an important step in Audi’s development of alternative fuel vehicles. While CNG adoption remains limited in some regions, the 40 g-tron demonstrated Audi’s commitment to reducing emissions and offering customers more sustainable transportation options. On the used car market, these models are generally well-regarded for their reliability and fuel efficiency. The EA888 engine is known for its durability, and the S tronic transmission is generally reliable when properly maintained. The 40 g-tron’s unique bi-fuel capability and environmentally conscious design continue to appeal to a niche market of buyers seeking a practical and sustainable grand tourer.
