2020 Audi A4 review - Engine and Gearbox

Still not the driver’s car of the class, but the A4 is strong in all other areas

Evo rating
  • Refined, well built, competitive engines, S4’s strong performance
  • Rivals are more entertaining, messy styling details

Engine, transmission and technical details

The A4 range will eventually comprise seven engine variants, three gearbox options and a choice of either front-wheel drive or quattro all-wheel drive, but for the time being Audi has released full details on only a selection of those.

Those are, in turn, the 35 TFSI, 40 TFSI, 40 TDI, and the S4 models, both of which also use TDI engines. After a couple of years of Audi’s new model designation system we’re still little the wiser, but broadly the double-digit numbers refer to a power category (though don’t directly correspond to any output), while TFSI and TDI refer to the firm’s petrol and diesel engines.

In the A4, the 35 TFSI is a 2-litre turbocharged in-line four developing 148bhp from 3900 to 6000rpm, and 199lb ft of torque from 1350 to 3900rpm. It’s available with a choice of six-speed manual or seven-speed S-tronic transmissions, the latter being Audi-speak for a dual-clutch auto.

Move up to the 40 TFSI and you still get two litres and four cylinders, but now power climbs to 187bhp at 4200-6000rpm, and more torque too – 236lb ft from 1450 to 4200rpm. A seven-speed S-tronic is the sole transmission available, and drive is still sent to the front wheels alone.

Quattro all-wheel drive first becomes available with the 40 TDI, which matches the 40 TFSI’s power output at 187bhp, but develops it instead at 3800-4200rpm, a narrower band than with the petrol. Likewise its torque spread is less broad than that of the petrol, but it’s more muscular too – 295lb ft at 1750-3000rpm. A seven-speed dual-clutch is the only gearbox available.

The S4 tops the range, giving you more of everything – capacity, cylinders, power and torque. Those numbers are, in turn, three litres (2967cc), six cylinders (in a V formation), 342bhp (at 3850rpm), and a massive 516lb ft of torque (at 2500-3100rpm). Quattro all-wheel drive is again standard, with a self-locking centre diff and optional sports differential at the rear axle, while the transmission is an eight-speed torque-converter auto, badged Tiptronic.

The 40 TDI and S4 aside, all the above use a 12V ‘mild-hybrid’ system to help run ancillaries and mildly reduce fuel consumption. The 40 TDI does without such systems, while the S4 gets a more powerful 48V mild-hybrid set-up, with a belt-driven starter-alternator, as well as an electrically powered compressor to boost torque and response at low engine revs.

As this generation of A4 is primarily a styling and engine update, there’s been little change to the platform – the A4 remains a steel and aluminium-bodied four-door saloon or five-door estate, with longitudinally mounted engines and a choice of front- or all-wheel drive. Suspension is five-link at each corner, with front and rear anti-roll bars, optional adaptive dampers, and electrically assisted power steering.

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