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
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.