Suzuki Swift: Fourth Report

Choosing between a petrol and diesel model is simple, right? Traditionally, oil-burners delivered better fuel economy, while petrol cars served up improved refinement and a sportier driving experience. Nowadays, it’s not quite so black and white, though – as we discovered when we dusted off our calculator.

Suzuki has recently added a diesel model to the Swift range, and that got us thinking. How does the oil-burner compare to our petrol long-termer? And do the sums really add up? On the face of it, the new Swift 1.3 DDiS promises some big savings at the pumps, with combined economy of 67.3mpg, compared to 56.5mpg for our 1.2-litre petrol.

But delve a little deeper – taking into account the purchase price and road tax bills, as well as the predicted residual value – and it’s not as clear cut as you might think. We crunched the numbers for the 1.3 DDiS, which comes only in SZ3 trim, and the equivalent model fitted with the 1.2-litre petrol unit (our long-termer is a top-spec SZ4). The results were fascinating. Over the course of three years, I reckon you’d need to drive at least 12,156 miles annually to justify buying the diesel. As the average UK motorist does about 12,000 miles a year, the lesson here is simple – if you cover a lot of ground, go for the diesel. But there’s much more to running a car every day than some raw figures.

For a supermini like the Swift, owners are less likely to cover big motorway miles, and will mostly use it around town. Above all, though, the fizzy little petrol engine suits the Suzuki’s playful character so much better. It needs to be revved hard to produce its best – unlike the diesel, which has much more torque at low revs. Still, that’s what gives the petrol car its energetic personality and keeps the keys changing hands constantly in the office. For what it’s worth, the diesel version uses the same engine as the Fiat Panda, but it’s more refined in the Suzuki.

The hard-working Swift has picked up a few battle scars along the way, including scratches to the front bumper and a scrape on the front wing. Both are classic symptoms of careless parking –unforgivable, given the compact dimensions and great visibility.

We’ll get them fixed before we hand back the keys, but the rest of the package its as polished as it was on the day it arrived, without a squeak or rattle to be found.

What continues to impress is the Swift’s ability to dart around town and make city traffic less of a chore. Yet it also dispatches longer motorway journeys with ease – staying comfortable and quiet, pulling only 3,000rpm at 70mph. The excellent kit list makes all the difference on the open road, too.

The iPod connector is in constant use, while cruise control helps fight off tiredness on big trips. Even in the face of stiff competition from its own family, the Swift keeps putting a smile on our faces – and it’s reassuring to know that the sums add up.

Video: watch CarBuyer's video review of the Suzuki Swift