Currently reading: Audi S4 and S4 Avant gain new 342bhp mild-hybrid diesel
New diesel powertrain gives BMW M340i rival 516lb ft of torque, reduced fuel consumption and CO2 emissions

The range-topping Audi S4 saloon and Avant estate models will be offered with a 342bhp mild-hybrid turbocharged diesel V6 engine.

The new powertrain will match a 3.0-litre V6 TDI diesel with a 48V belt-driven starter motor end electrically powered compressor. As well as producing 342bhp, the system produces 516lb ft of torque, allowing the S4 saloon to achieve 0-62mph in 4.8 secs, with a limited top speed of 155mph. The Avant is 0.1sec slower to reach 62mph.

Both versions of the Mercedes-AMG C43 rival will retain Audi's quattro four-wheel-drive system and use an eight-speed automatic gearbox.

Audi lists a fuel consumption of 45.5mpg for the S4 saloon and 44.8mpg for the estate. CO2 emissions range from 161-163g/km and 164-164g/km CO2 respectively.

The mild hybrid diesel engine is the same as that recently introduced on the S5, S6 and S7 Sportback models, albeit in a moderately different state of tune, with 342bhp. It's the only engine that will be offered in the European market for those models, and it's likely that Audi will continue that trend with the S4, given the need to meet new WLTP tests and fleet emission targets.

Audi is currently preparing updated versions of the regular A4 saloon and Avant models, which have been spied testing with a number of styling tweaks and are likely to be revealed later this year.

Read more

Audi S5 switches to 342bhp mild-hybrid diesel

Audi reveals S6 and S7 Sportback with new diesel powertrain

Audi preparing bigger A4 and A4 Avant updates for 2020


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James Attwood

James Attwood, digital editor
Title: Acting magazine editor

James is Autocar's acting magazine editor. Having served in that role since June 2023, he is in charge of the day-to-day running of the world's oldest car magazine, and regularly interviews some of the biggest names in the industry to secure news and features, such as his world exclusive look into production of Volkswagen currywurst. Really.

Before first joining Autocar in 2017, James spent more than a decade in motorsport journalist, working on Autosport,, F1 Racing and Motorsport News, covering everything from club rallying to top-level international events. He also spent 18 months running Move Electric, Haymarket's e-mobility title, where he developed knowledge of the e-bike and e-scooter markets. 

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Ancient1 2 May 2019

Audi B9 S4 TDI

Really, 342BHP - but is that actually BHP, HP or PS?.

My copy of the Audi Media Centre release clearly states 255kw (347hp) & up to 700nm, which makes it the SAME tune diesel that is in the S5, SQ5, S6 & S7.

These diesels have no connection with 'Dieselgate', as they are brand new engines with a number of areas of development incl Audi's woefully poor version of mild-hybrid and a larger turbo in attempting to overcome the extra 150kgs.

Of course the diesel engine is cleaner & more economical than the equivalent petrol engine.  Audi needs it to be pass the EU emissions & economy, whilst the rest of the world still gets the dirtier, but quicker, petrol engine.

We've had these Audi Media releases for some months now, but there does not appear to be one half-professional journalist who can advise why Audi needs heavier, slower diesels to pass regulations, whilst their competitors, Merc & BMW appear to be fine with petrol engines.

Also dimensionly where & why is the bootspace decreasing 60l. 

405line 2 May 2019

One thing is guaranteed

and that is it will be very light and really responsive with hardly any unsprung mass. 516ft/lb is all that is required

SamVimes1972 2 May 2019

Looks like I can now add the

Looks like I can now add the S4 Avant to the list when I next change. For every customer they lose I can guarantee there is a high mileage driver waiting for this switch.