Once you get over the shock of realising Volkswagen's new Jetta saloon comes from the land of tequila and not from the birthplace of schnapps, it does not take long to spot the sparkle that lurks under the skin of this sober-looking booted Golf. If its Bora predecessor is any guide it will do well. Rather boring in form, the Bora was a popular choice among tens of thousands of buyers who appreciated the elegance of a three-box design and the carrying capacity it delivered.My test car is set to become the top-seller in the Jetta range - the two-litre TDI SE with a lively 138bhp and a slick six-speed gearbox. It's a well-specified model with excellent safety credentials and an on-the-road price tag of £17,525. And for anyone nervous about Volkswagen's decision to build the Jetta in Mexico at its Puebla plant, let me reassure them that build quality is first-class and up to the standards of recent Golfs.The new Jetta family is priced from £14,636 to £19,990 and replaces the Bora, which sold 57,913 examples during its six-year life. That's far better than the dreadful Vento it replaced, which was as popular as a building brick in a kite-flying contest and managed to find barely 12,000 buyers in its six-year reign.But this is not the first time the Jetta moniker has graced a Volkswagen saloon. In 1980 the first booted version of the Golf arrived on the scene bearing the Jetta badge. It established itself as a high-pressure seller thanks to its innovative use of a turbocharged diesel engine - the first of its kind and forerunner of today's industry-leading PD TDI 16-valve Volkswagen oil burners - and sold an impressive 76,441 units until its demise in 1992.The current Jetta is a far more refined and elegant car. Even in its entry-level trim with 115bhp 1.6 litre FSI power, the Jetta S is loaded with equipment and drives quietly on an advanced new suspension system. The dash is plain, but well laid-out, beautifully assembled and functional.Jetta is bigger than the Bora - 17.8cm longer, 4.6cm wider and 1.3cm taller. The wheelbase has grown by 5.9cm, helping bring better space and a more settled ride. Quieter, smoother and roomier, it also has a bigger boot, up 72 litres to a massive 527 litres. That’s 42 litres more than the new Passat. Fold the 60/40 split rear seats and the back of the car turns into an impressive cargo floor which is almost, but disappointingly not quite, flat.The twin-cam TDI is a direct injection turbodiesel with a remarkable output. Power is backed up with 236lb/ft of torque bang in the useful working range between 1750 and 2500rpm. That means brisk acceleration through the gears for overtaking, despite the load, and an easy motorway cruise. The PD unit injector engine features a crossflow cylinder head which helps deliver a silky smooth drive, aided by a six-speed manual gearbox with three-cone synchromesh on the lower ratios for slick changes and low drag.It all adds up to a relaxed drive and economy which can touch 40mpg around town and nudge 60mpg on the open road. Even brisk driving will give the Jetta 2.0 TDI a tank-to-tank range of over 600 miles on its 12-gallon diesel reservoir.Like other Volkswagens the Jetta 2.0 TDI can be serviced in two ways: time and distance with work carried out every year or at 10,000 miles, or on the maker's variable Longlife service regime. The latter uses on-board computer technology to determine when servicing is needed. In ideal circumstances some diesels will be able to run for up to 30,000 miles or two years between servicing.Of the three trim levels (S, SE and Sport), SE offers best value. On top of the packed standard specification which includes a driving computer, it gains 16" alloys, "comfort" front seats with height and lumbar adjustment, under-seat drawers, leather-trimmed steering wheel and gear gaiter, cruise control, rear air vents and cup holders, a central front armrest with 12-volt socket, another 12-volt socket in the boot and a radio/CD player with eight speakers.Apart from the car's solid feel and quality trim, I was mightily impressed by its comfort and well-controlled ride. Coupled with powerful brakes and electro-mechanical power steering the car is good to drive. Gentle understeer through a fast corner is hardly a vice. And thanks to its torsionally stiff body I even found the suspension's tendency to float mildly over some undulating surfaces acceptable because of the overall feeling of security.Volkswagen says it will sell 8000 Jettas a year in the UK. 55% of them are expected to find their way onto fleets and 80% to be diesel-fuelled. I can't argue with those figures, especially with the 2.0 TDI SE. It's an elegantly understated, if aesthetically unexciting, booted saloon which drives well, delivers impressive safety equipment, a high specification and will appeal to those looking for a roomy and comfortable halfway house between a Golf and a Passat. In many ways the Jetta is a better car, by far, than both. Engine 1968cc, 4 cylinders Power 138bhp Transmission 6-speed manual Fuel/CO2 48.7mpg / 157g/km Acceleration 0-62mph: 9.7 seconds Top speed 129mph Price £17,525 Details correct at publication date