A PLUG-IN hybrid power system with an electric-only range of almost 90 miles has been developed by Audi and will make its debut in the new A3 Sportback 40 TFSI e.

Priced from £39,150 the newcomer is one of the longest range PHEVs and has a theoretical fuel economy of between 706.2 and 941.6mpg. Emissions are as low as six g/km.

The official maximum EV range of the A3 Sportback 40 TFSI is 88 miles on a fully charged battery.

The car uses the latest 1.5-litre TFSI evo2 combustion engine, which has a power output of 150ps and combined with the electric motor, peak power is 204ps.

It gives the A3 a 0-62mph acceleration time of 7.4 seconds and a top speed of 140mph. The all-electric top speed is 87mph.

Audi presented extensive upgrades for the A3 and S3 in the spring of 2024 and the A3Sportback40 TFSIe now follows with a more powerful and efficient plug-in hybrid powertrain.

The 1.5TFSIevo2 replaces the previous 1.4TFSI and comes with a wide range of high-tech features.

In addition to optimizing combustion chamber cooling, the combination of the turbocharger with variable turbine geometry and the Miller cycle, as well as the early closing of the intake valves, ensures a higher compression ratio. The ratio is now 11.5:1, compared to 10:1 in the 1.4TFSI.

Thanks to this combustion process, the new unit operates with a high degree of efficiency, reducing fuel consumption and emissions. Injection takes place at a pressure of up to 350bar. By comparison, the 1.4TFSI engine reached a maximum of 200bar.

Depending on the situation, the A3 Sportback 40 TFSI e can coast, recuperate - both under acceleration and braking - or boost together with the electric motor and the petrol engine.

Releasing the accelerator the A3 Sportback 40 TFSI e coasts with the engines switched off, or the electric motor recuperates in overrun mode and like all of Audi's all-electric models, the steering wheel paddles are used to control the degree of recuperation in EV mode.

Recharging can now be done from a DC outlet and 10 to 80 per cent recuperation can be done in less than 30 minutes. A full charge from a home charger takes 2.5 hours.

Like the rest of the A3 lineup, the plug-in hybrid powertrain is offered in Sport, S line, and Black Edition specifications with the latter two costing from £41,430 and £42,880 respectively.

As well as features such as the Audi drive select dynamic handling system the PHEV has special displays to provide information about the drive with a graphically revised power metre in the virtual cockpit that shows the power currently being called up, the drive mode, the battery charge status, and the range. The MMI display also visualises the energy flows.