Volkswagen's turbocharged and supercharged 1.4-litre TSI engine has the performance and economy bases well covered. Coupled with the Jetta saloon bodystyle, it won't sell as strongly as it will in the Golf but buyers venturing beyond the mainstream will find a solid all-round package with a more grown-up feel than the hatchback alternative.

Here we look at a compact saloon with an economical 1.4-litre engine. Not the most inspiring introduction is it? Half the readership will already have wandered off to do something more stimulating like varnishing their banisters or tearing the newspaper into long, thin strips while staring into the middle distance. The compact saloon in question is a Volkswagen Jetta. It's no good, we're still haemorrhaging interest like a Maths teacher in the last lesson before the summer holidays. The economical 1.4-litre engine uses a supercharger and a turbocharger to produce up to 168bhp and a hefty 240Nm of torque. It can fire the Jetta from 0-60mph in 8.3 seconds, reach a 138mph top speed and still return around 40mpg. Gotcha!

The British don't have much affinity with small saloon cars, even when they are based on the top-selling Volkswagen Golf platform, so the Jetta was always going to have its work cut out in drawing attention to itself. That said, if any powerplant in the prodigious Volkswagen Group armoury can give the car the sales boost it needs, you'd back the 1.4-litre TSI. Economy, refinement, performance, it's got the lot.

If you hadn't already sneaked a peak at the spec sheet, there's no way you'd finger the Jetta TSI's engine as having a 1.4-litre capacity. It feels like a much larger turbocharged petrol unit but the pull at the lower end of the rev range is almost diesel-like in its muscularity and the economy has more than a touch of the oil-burner about it but the upper extremities of the rev range have plenty to offer. It all helps to make the Jetta TSI genuinely satisfying to hustle along a B-road whether you're at the wheel of the TSI 140 or the TSI 170. The Jetta is actually stiffer than the Golf hatch and this helps the chassis remain highly composed in corners. There's also an impressive suppleness in the way the springs absorb bumps. Some noise does emanate from the suspension over really bad surfaces but the audible thumps are only felt as minor vibrations buy the driver. The Sport models get firmed-up suspension that's more jittery but sharpens up the handling nicely.

"There's no way you'd finger the Jetta TSI's engine as having a 1.4-litre capacity"

The TSI engine's supercharger operates at a maximum of 1.8 bar pressure, boosting the low end torque response where turbo cars can often feel lethargic. Once the supercharger has done its bit, the turbo kicks in for high-end power. With the faster powerplant, the peak power figure of 168bhp arrives at 6,000rpm, whereas the maximum torque peak of 240Nm is retained all the way from 1,750 to 4,500rpm. This makes a flexible and inherently driveable engine with the strength to negate the need for constant gear swapping at low speeds and the top end performance that really makes you want to cut loose. There's a satisfying engine note when you extend the TSI unit too but the engine may be slightly vocal for some tastes.

Viewed from the front, the Jetta is just like a Golf except for the chrome section inserted below the grille. Progress round to the rear though and the protruding boot will hove into view. Your take on this will depend on your perspective. In many European countries, the saloon bodystyle equals class and prestige in comparison to the shopping trolley hatch. Over here, the commonly held view is that it spoils the lines and the practicality of a perfectly good hatchback. Take your pick. The Jetta's interior is a little plusher than standard Golf fare, although the basic architecture of the dashboard is the same. With the possible exception of its pricier Volkswagen Group cousin, the Audi A3, the cabin has the beating of anything out there as regards ambience.

The interior features soft-feel slush-moulded plastics, high-quality switches, subtle use of chrome, fabric-covered A-pillars plus blue instrument backlighting with red needles, a signature of the fourth generation model. Cabin space is superior to that in the Golf and the rear seat passengers benefit most. The boot itself is large enough to make you question the need for a hatch at 527 litres. That makes it more capacious than the boot of a BMW 7 Series. For extra flexibility, the 60/40 split rear back-rest can be folded forwards to form an almost flat floor up to the front seats.

Assuming you don't want the turbo-only 122bhp 1.4 TSI engine used in entry-level Jettas, as we've already intimated, there are two engine options for Jetta TSI buyers to decide between - the 140 and 170 versions of the unit. You'll have to step up from the entry-level S trim level in order to get either with the 140bhp TSI being offered in mid-range SE guise and the 170bhp option available exclusively as a range-topping Sport model. Prices start at £16,665 for the 140 and £18,275 for the 170. All models get air conditioning, alloy wheels, a six-speaker CD stereo, trip computer and electric windows all-round.

The SE models add an extra sheen of class to the Jetta with alloy wheels, body-coloured rubbing strips on the bumpers that also feature chrome inserts and chrome wing mirror surrounds. The interior materials are also upgraded and the specification is upped to include cruise control, an upgraded stereo and loads more storage options. The Sport has bigger alloys, sports seats, front fog lights and sports suspension that's lowered by 15mm.

The fuel economy served up by the Jetta TSI derivatives would be some way below average for a 1.4-litre petrol-powered family car but it's outstanding for a 1.4-litre petrol-powered family car packing this kind of performance. The official combined economy figures are 39.8mpg and 38.7mpg for the TSI 140 and TSI 170 engines respectively. The difference between the two being minimal, buyers have an extra incentive to make the leap up to the more powerful engine.

If you opt for the excellent DSG twin-clutch automatic gearbox, economy actually improves but emissions are measured at 169g/km for the TSI 140 and 174g/km for the TSI 170 whichever transmission you choose. The Jetta will depreciate more vigorously than an equivalent Golf because most Brits like their small cars with hatchback rather than a boot but the Jetta's relative rarity out on the roads will add to its appeal for many.

Judged purely on its engineering, the Jetta TSI is an outstanding piece of work on Volkswagen's part. The 1.4-litre supercharged and turbocharged engine is a groundbreaking effort whichever way you look at it. Few cars in the class can hold a candle to the driving dynamics and build quality is typically rock solid. The question is whether UK buyers will want it all wrapped up in a booted Jetta costume when they can have the same car packaged as a Golf?

We already know the answer and it is that the Golf TSI models will dramatically outsell the Jettas for the simple reason that we just don't understand the appeal of the small saloon car in this country. This makes the Jetta something of a leftfield choice and that in itself will attract a certain type of customer. The extra element of luxury, that large boot and the additional cabin space will also help persuade people to forgo the pleasures of a hatch. It all means that the Jetta, particularly in TSI form, is more than worth its place in the Volkswagen line-up.

TOP 2 JETTA DEALS

The results below show the top JETTA deals on buyacar

	Volkswagen Jetta 1.4 S TSI 4dr [122] Saloon
	ETR	Mthly £249	Saving £2,013	Price £13,122
	Volkswagen Jetta 1.4 SE TSI 4dr [122] Saloon
	ETR	Mthly £266	Saving £2,123	Price £14,012

typical 10.54% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000