With engine sizes seemingly in freefall, partly to meet ever-tightening emissions legislation, partly to increase frugality, Iain Robertson puts the ‘brand of the moment’s’ compact family model through its paces in a week of 1,000-miles.

According to the blurb from Kia Cars, the new Kia Stonic is ‘exciting, sporty, smart and confident’. While I have no issue with its captivating good looks, its youthful zestiness and slightly jiggly ride quality, which arises from spring and damper settings that are geared more towards sporty progress, than sublime comfort, a major question surrounds a concern that I harbour for its overall durability.

Small capacity petrol engines have been a mainstay of the British car industry for well over half a century. If you ever had experience of the original Mini 850’s bumbling 30bhp, then you would appreciate that only modest progress was on its cards, possessing a top speed of around 78mph and a yawningly slow 0-60mph time of more than half a minute. Fortunately, developments have been rife over the intervening years.

For a long time, the typical power output of a 1.6-litre petrol engine was around 85-90bhp. It was enough to make the archetypal company-owned Ford Cortina, Vauxhall Cavalier, VW Passat, Citroen BX and Peugeot 405 zippy enough to entertain the ‘rep’ but also to keep the speeding tickets at bay. The 2.0-litre fuel-injected alternatives were the premise of the sales manager and sporty SRi, S and even GTi variants proliferated on the nation’s roads, giving in part some hope to the drudgery of selling biscuits, sweeties and household items experienced by thousands of lower-grade employees, many of whom were only too grateful to have a ‘free’ car supplied.

While the company car sector remains vital to the UK economy, it is one now predominated by choice and the growth of the ‘user-chooser’ market meant that a fleet manager could be perceived as providing some advantages to staff, while maintaining well-balanced accounts. Yet, it could be stated that a tipping-point has been reached and, while cash-for-cars is a growing phenomenon, the tax levies related to Benefit-In-Kind on company supplied vehicles being so steep that it can be the preferable option for salaried employees, the demand for a smaller, more frugal option has grown exponentially.

The industry’s response was immediate, with a proliferation of 1.0-litre, three-cylinder, turbocharged-petrol models weighing into the market from almost every volume manufacturer. However, some of their power outputs have now breached a long-standing level of 100bhp/litre by considerable margins. There was a time, when an engine’s efficiency and efficacy was judged to be at its peak, when 160bhp was claimed for the 1.6-litre version of the Honda CRX sporty coupe of the late-1980s. Observers anticipated that these steel-cranked, balanced-rods, multi-valved, steroid-enhanced high-revvers were doomed to failure in short order, as not so long beforehand, 100bhp/litre was considered to be more than adequate for a racing car.

However, perceptions and expectations have altered accordingly. My own Suzuki Baleno boasts a cool 109bhp from its zippy 1.0-litre capacity, accompanied by a strident 125lbs ft of torque. Put into perspective, the same 998cc engine size in a 1978 Mini 1000 resulted in a mere 39bhp and 51lbs ft…with one cylinder more, four valves and an intercooled turbocharger less. The latest Kia Stonic develops 118bhp and 126lbs ft. The only reason it is less zesty than my Baleno is because it weighs around 20% more.

Interestingly, unlike the 8,500rpm maximum rev-ability of the aforementioned 1989 Honda, both Baleno and Stonic are limited to a less frenetic 6,000rpm. Intriguingly, the in-period Honda had a torque figure of just 112lbs ft developed at a sky-high 7,100rpm, whereas both of the 1.0-litre ‘tiddlers’ develop their torque (pulling potency) over flatter curves, from little more than 1,500rpm to around 3,500rpm. The Honda would scarcely pull the skin off a rice pudding, while the Stonic and Baleno can tow a tonne of caravan apiece.

All of this bodes well for the proposed greater longevity of the 1.0-litre units. Yet, it is suggested that the driving quality of the smaller, less weighty engine can denigrate, as the miles are piled-on. On just one of my trips carried out on a single day, I departed my home in Lincolnshire and drove to Brighton and back, a total distance of 440-miles (if repeated daily, a total of 160,600-miles annually). The Stonic performed faultlessly in sub-zero temperatures, returning a modest 44.9mpg overall (the Mini would have performed similarly but not as speedily).

A 220-miles round-trip to Birmingham was next, which involved substantial delays on the M42 – 46.7mpg. A return trip to Leeds factored-in 175-miles (44.8mpg), while two separate trips into the Derbyshire Dales added another 212-miles to the five-day mix (43.7mpg).

While I am always vigilant for speed cameras, of which there were a few, static, average and mobile types, I was forced to dig deeply into the Stonic’s performance envelope (0-60mph in 9.9s, 115mph maximum speed), which did affect the week-long fuel return (56.5mpg Official Combined). Yet, at 45.0mpg, while being 20% less than the posted figure, I do not consider the Stonic to be excessively thirsty.

Cramming 1,047 miles into a five-day working week equates to an annual business mileage of 52,350; add in local weekend running and the total could reach as much as 60,000, which could be fairly described as high mileage. At no time did the Kia’s tiny engine display characteristics of fatigue, thanks to fairly high overall gearing that meant a 70mph cruise demanded only a whisker over 2,400rpm, a mere 40% of its maximum viable engine speed, which it will maintain on a whisker of throttle, thanks to a moderate drag coefficient of 0.34Cd.

It should be highlighted that I did not feel tired, while driving the Stonic, which suggests that the seating position is good and alighting from and returning to the driver’s seat was an accessible pleasure. On those occasions, when I carried passengers, they did not complain either and everyone declared that they quite enjoyed the slightly off-beat thrum of the three-cylinder engine and that they were amazed at its relative zest.

Naturally, in the UK there are very few locations where high-speeds can be maintained safely and for long-ish distances. Most of the time, we are forced to endure 55-60mph in the outside lanes of dual-carriageways, lower speeds behind overtaking trucks, which ensures that most planned drives need to be worked out on a 45-50mph average, if using main roads (35-40mph for A-roads) although fast and safe overtaking on country roads is only possible by using all of the available punch.

Conclusions:   Modern small capacity petrol engines are not simply tougher and more durable than you might believe them to be but they exceed expectations in performance terms. The top speeds are excellent and legal limit cruising (aided by distance cruise technology) seldom demands more than 40% of the engine’s potential. Of course, constant hard thrash will result in failures, probably at around 120-150,000-miles but repairs are unlikely to be catastrophic, as long as regular servicing is carried out. The Kia Stonic 1.0T-GDi is a prime example of a compact family car that delivers disproportionately to expectations. It is an excellent machine.