Talking of the hybrid system, it could end up making quite a difference to economy in the S5. Low-speed running is where a powerful petrol engine gets very inefficient and doesn’t even give you back much in sound or character. If you can shut it down and run on electricity instead, that’s a win-win.
Indeed, in our limited testing, the S5 seemed capable of 40mpg when taking it easy. The regen is very gradual and the motor emits quite a characterful whine when operating.
The rest of the time, the hybrid stuff just fades into the background and you have a proper engine – one that doesn’t need plugging in to work properly. The tech’s promise of good throttle response mostly materialises and the engine picks up nicely. It sounds good too – not mind-blowing but tuneful enough, with more grit than Mercedes’ and BMW’s ultra-smooth straight sixes.
Naturally, there’s plenty of performance, and the ’box responds well to the paddles. It doesn’t really provide any meaningful improvements over the old auto, though: the shifts are a touch soft when you’re going for it, it upshifts automatically at the redline and it’s occasionally slightly clunky in town.
The diesel also gets the hybrid system, and it works well here too, even if the fuel savings aren't spectacular. The WLTP figure for a front-wheel-drive, 201bhp A5 Avant is 53.3mpg, which is the same as for the Skoda Superb Estate with an unhybridised 148bhp version of the same engine. In other words, you get an extra 53bhp for no fuel economy penalty. In practice, my test car returned high-40s on a mixed loop and appeared capable of low-50s at a motorway cruise.
It's a very pleasant engine, though. Although it’s clattery from cold, the 2.0-litre diesel four quietens down as it warms up, and provides plenty of effortless shove.
Audi says diesel sales in the UK will likely linger in the single-figure percentages, but it’s continuing to offer them because they’re still popular in Germany and even that quiet UK business will mean a few hundred sales not going to BMW, which has pulled the 320d and 330d from the market. The vast majority of UK-bound A5s will be 2.0 TSIs, which we've only driven very briefly so far.
With 148bhp, the entry-level A5 gets out of its own way well enough, but it just doesn’t have much in reserve and sounds quite strained and thrashy when you inevitably have to push it. Upgrading to the 201bhp version therefore seems sensible.
Audi’s engineers told us that they hadn’t put the hybrid system on the 2.0-litre petrol to keep costs down on what is the entry-level offering, which checks out when you look at the price premium for the diesel.
