It’s all change for the Audi A4 or rather its new name, A5. But wasn’t there already an A5? Indeed there was, that being the A5 Sportback, a larger model, now discontinued along with the A4 Saloon and A4 Avant.

Formerly a four-door car, plus of course five doors for the estate, the A4 Saloon has become the A5 Saloon. But here is where it gets a touch confusing, for despite the name, this is not a saloon, it’s a hatchback. Audi has also replaced the old S models with a new S5 Saloon and S5 Avant. An RS 5 is coming too, likely later this year.

Still aimed at the C-Class and 3 Series

Will buyers be confused by the shift to a higher number? Probably not too much and what matters most is just how good the new model line is. And it is very good indeed.

Recently, I tried the new A5 Avant in high-priced (£58,895) Launch Edition form, powered by a fresh evolution of the Volkswagen Group’s long-running 1,968 cc four-cylinder diesel. Compression-ignition engines might be rapidly vanishing from many OEMs’ passenger vehicle portfolios but they will remain available in Audis (and VWs) for several more years.

Outputs for the longitudinally-mounted 2.0-litre TDI are 150 kW (204 PS) and 400 Nm, torque being sent to the front axle via a seven-speed S tronic (dual clutch transmission). Zero to sixty two mph takes only 7.7 seconds and top speed is 149 mph.

Almost sixty mpg

Audi says CO2 is 138 g/km, though for cheaper trims it can be as low as 130 and the same applies to average Combined economy which ranges between an official 53.3 and 56.6 mpg. Yet I found it easy to get close to sixty miles per gallon. In a world of ever more electrified petrol cars, which don’t always have big torque outputs, this diesel engine is both novel and a revelation.

The new A5 is no lightweight, tipping the scales at 1,835 kilos in Launch Edition form, making that fuel consumption all the more remarkable. How is this achieved? The answer is a fascinating take on what defines an MHEV system.

Just like a series hybrid, this new mild one allows partially electric driving, the engine not being activated when you start the car and move off. In that sense, this is therefore that extraordinary thing, a silent diesel. Then, even when it does fire up after a hundred metres or so, there’s no vibration though the steering wheel, just a now-detectable mechanical sound up front. And quite a pleasing one at that.

Big torque from an electric motor

Called MHEV plus, there is a 48-volt electrical system and a 1.7 kWh (gross) LFP battery. The no-engine at start-up is made possible by linking the PTG or powertrain generator, BAS (belt alternator starter) and battery. Conversely, when power is required for, say, overtaking – in this case up to 18 kW/24 PS plus 230 Nm – it is there too, at speeds up to 87 mph. Further, as much as 25 kW is stated as being generated and harvested by braking deceleration.

The engine is also allowed to idle or ‘coast’ as Audi terms this, when the driver lifts their foot from the throttle pedal. Once you get into this habit and see the average MPG read-out rising, it can become quite a satisfying thing to do. Equally, even forgetting about economy, the A5 TDI will still return forty-plus mpg.

Petrol PHEV on the way

Efficiency and durability have been prioritised via liquid cooling for the motor and power electronics. In practice, all this technical wizardry is seamless in action. You could even forget that there is a diesel engine working away, so silent is it. Petrol power is available too and more options, such as PHEV, are to come later in 2025.

Audi hasn’t forgotten to add driver appeal into the mix either, the A5 handling far better than some might expect given its front-drive bias. The roads on my test route have become even further damaged than they were before the recent heavy rain yet the Audi’s suspension coped exceedingly well with everything thrown at it.

When it comes to the interior, you immediately know what brand of car this is, even without seeing the four rings on the steering wheel. Shapes are familiar from other Audis, there are up to three screens, lots of soft-dark plastics and firm seats. Perhaps a little less gloss-black trim would be better, this being prone to showing finger marks. But all in all, it’s nicely premium and there are a decent number of functions which don’t default to screen-only activation.

Special model for China

Its maker no doubt hopes that the new A5 will become a global best-seller, taking steps to ensure that regional differences are accommodated. So it is that the TDI will not be offered in the USA, while China, via the FAW joint venture, has a lengthened model, the 4,902 mm long A5L which is an actual sedan.

Conclusion

Even with the UK becoming the largest market in Europe for EVs in 2024 (381,970 versus 380,609 for Germany) it’s clear that demand for liquid-fuel passenger cars remains high. State of the art ones such as the new A5 2.0 TDI remind us that the best diesel models still have a lot to offer. That means low levels of emissions as well as the extraordinary economy which has always been the big attraction of compression-ignition engines.