Vauxhall's new 'whisper diesel' engine, which is now also available in the Astra, is all very hush-hush, says motoring editor Andy Russell.

The last green Vauxhall Astra I had driven was my wife's old company car. Like the shiny new test car it was green – we called her car's pale shade 'seasick green' – and an estate, although now it's a Sports Tourer... much more exciting than a humble estate.

Her Astra came off the production line 30 years ago and the modern Astra is a very different beast but still a willing workhorse which is why it finds favour with private buyers and business-users.

The other thing in common is that both had a 1.6-litre diesel – a naturally-aspirated unit in my wife's car that was more shake, rattle and roll than smooth operator.

It was difficult to come to terms with the fact this new Vauxhall was actually diesel – Vauxhall's new 'whisper diesel' which lives up to its name with its hush-hush approach which should appeal to high-mileage drivers. Launched in the Zafira Tourer, it then went into the Meriva and is now available in Astra hatchback and Sports Tourer estate in 110 and 136PS outputs, virtually mirroring those of the long-serving 1.7-litre turbo diesel.

While the 1.7-litre unit is showing its age, the new 1.6-litre diesel, which costs only a couple of hundred pounds more model for model, is Euro 6 compliant so meets forthcoming emissions standards with a trap for nitrous oxide (NOx). It is also one of the best engines in its class for noise and vibration.

But it isn't all green and no grunt for Vauxhall's cleanest ever mid-size diesel pulls willingly and smoothly from very low revs, making it relaxing to drive, and has enough mid-range punch to make light work of overtaking. Even with some hard use the 136PS version returned 60mpg overall with a best of 65mpg.

The latest Astra is also much better to drive with competent handling, confident cornering and a comfortable, absorbent ride. But the muted engine makes tyre noise more noticeable – a problem with many modern cars with harder compounds and higher tyre pressure to maximise economy and minimise emissions not combining well with rough road surfaces.

It's also the best looking Astra, inside and out, and a much more attractive fascia but let's hope that, like the Insignia, the next facelift will remove some of the small fiddly buttons. Rear visibility is fine but chunky front pillars make seeing the kerb on roundabouts difficult.

The spacious interior is geared for passengers and loads with decent legroom and a well-shaped 500-litre loadbay which trebles in size with the 60/40 split rear seats backs folded flat. With no spare wheel there is also underfloor storage.

Vauxhall's new whisper diesel makes a strong case for itself – easy on the ear and the wallet.