The Next Audi S4 Will Be Diesel For The First Time

After the S7, S6 and S5 were all recently revealed with new mild hybrid powertrains, the S4 has followed along the same lines

Matt Kimberley

02 May 2019

The Next Audi S4 Will Be Diesel For The First Time

Audi has continued its run of converting S models to diesel with the new S4 and S4 Avant.

The compact saloon and its always cooler wagon brother will both come with the same 342bhp mild hybrid diesel engine that has already been dropped into the S5, the S6 and S7 solely for European markets.

Thanks to the electric generator/motor’s assistance the 3.0-litre V6 diesel – an Audi staple for years – has to work less hard and can therefore be more efficient. It harvests otherwise wasted energy under deceleration and sends it to a 48v battery that can then supply the motor with power when the driver gets back on the right-hand pedal.

There are only two pedals: the S4 will only use a specially-adapted eight-speed Tiptronic automatic that has extra software to cope with the mild hybrid’s extended functionality versus a stop-start setup. The engine will cut out when speeds drop to 13mph. Quattro all-wheel drive is standard as well, naturally.

Fuel economy is listed under WLTP testing as an achievable-sounding 45.5mpg for the saloon and 44.8mpg for the Avant. Far more interesting is the 516lb ft of torque on tap. In tandem with tall gearing it could make the diesel S4 a seriously rapid cross-country machine.

As for acceleration stats, the saloon will launch to 62mph in 4.8 seconds while the Avant takes a negligible tenth of a second longer.

We expect the next S3 to continue using the EA888 four-cylinder petrol engine; the V6 diesel won’t fit and the ever-evolving petrol lump is relatively efficient anyway. An updated version of the flagship S8 has yet to be revealed, though, and it will be interesting to see whether Audi goes diesel with that.

Historically the always-petrol S4 began life as the 1991 100 S4, which had a turbocharged 20-valve five-cylinder of 2.2 litres. It threw 227bhp at all four wheels and was joined in 1992 in some markets by an S4 Plus, which had an aluminium 4.2-litre V8 with 276bhp. New models switched to a twin-turbo 2.7-litre V6, then a normally-aspirated 4.2-litre V8, a 3.0-litre supercharged V6 and a turbocharged 3.0-litre V6 before the S range’s move to diesel.

Comments

The S4 has always been the underrated performance machine

I miss the S4 with the manual transmission
Otherwise, it would have been a good car if only people realized the manual is better than the auto

B5 S4 is my favourite

Hate diesels or not it’s amazing what Audi has achieved with.

Audis just became even less desirable for me

Yeah, I never thought they’d make a diesel

Have you reviewed the S4?
Maybe there’ll be a chance to review the diesel against the petrol and see if the move is justified

I would really love to see that

Still don’t understand this move from any angle - surely an EA888-based hybrid system would be almost as efficient, just as fast and more desirable and cheaper too!

Or imagine the 5 pot from the RS3, coupled with a mild hybrid system, sent through the latest quattro ultra AWD. In my mind that would be a perfect powertrain for a fast Audi.

Fast, efficient, and best of all - a Group B worthy soundtrack.

I believe it has to do with emissions. A lot of brands suddenly moved again to diesel since its the only way to lower a brands emissions on a short term. That’s what audi is doing, it’s an emergency move to excape heavy penalties.