A premium performance round our new Scottish route by the Premium 450 clinched the title for the French truck manufacturer.

EURO 4 has arrived and for some CV builders there have been teething troubles engineering new power plants to turn the drive axle with optimum torque. However, no such problems with Renault whose latest Premium model, in a gaffer's guise of 4x2 at 440hp, romped round the TN route in jig time.

But for a change, the story wasn't about spectacular fuel consumption or speed round the route, which were impressive enough: No, the big Premium plus was it's smooth as silk driveline, arguably the ultimate in tractor unit installation.

Certainly the latest version of Renault's fleet tractor unit received a whole host of plaudits from our official test commentary.

We described the 450.18 4x2LD T E4 as ‘pulling our concrete laden trailer eagerly and smoothly with just the right amount of noise feeding back into the calm and quiet confines of the cabin.

The demonstration vehicle came equipped with Renault's Optidriver+ gearbox pack, ably assisted by the Optibrake which combines the forces of the exhaust brake and engine valve brake retarder, delivering a superb stopping force.

As the day's goal was best possible fuel economy, we let the truck work away in full auto and it showed just how well sorted the system is, with ultra smooth changes keeping the truck in the green band of the rev counter and delivering the maximum 2,140Nm of torque between 1,100 and 1,300rpm, whenever required.

With fine winter sunshine and flat calm conditions, driving the Premium soon became a real pleasure and we quickly ticked off the M74, M73, M80 and M9 from our first leg as we cruised happily to the first timed hill climb on the A9 at Cairnie Brae, just after the Findo Gask road end.

The digital speedometer and dash display showed we dropped to 31mph in 10th gear on the climb, but again the Optidriver+ took it all in its stride and the truck pulled back effortlessly to top gear and set cruising speed quickly after the summit.

Time and again the auto shift gearbox excelled itself in slow speed situations and bumper to bumper traffic, with the throttle offering precise control down to the slowest of speeds, and no surprise up shifts or surges. The urban section of 34.23 miles would take 1 hour and 14 minutes to traverse and in the old days of clutched gear changes and brake pedal only, would have been definitely classed as hard work, but no so with the Premium as we climbed down from the cab wondering where the time had gone.

Like many truck manufacturers Renault took the Euro 4 opportunity to up its power and torque output, so the Euro 3, 440 eased up to 450hp and torque increased from 2,000Nm to 2,140Nm, all from the Volvo Group inspired 10.8 litre engine.

Next in the driveline is the Optidriver Plus, 12-speed automated gearbox, again with Volvo antecedents as part of the famous I-Shift transmission family. This has a ratio spread from direct drive to 14.95:1 and it all links to a single reduction 11,500kg Meritor rear axle (2.84:1 ratio).

The Optidriver shifts at an amazing speed – really ‘clutchless' between single gears and revs stay between 1,000 and 1,500, however if the driver wants to hit the floor Optidriver whisks the revs up and out of the economy band, up to 1,900 revs with a smooth block shift.

The circular route on the day of our test could easily be dubbed the ‘Premium route' as other similar French built models operated by TNT, MRS Distribution and Duncan Adams, to name but a few, seemed to be in abundance, giving us a real sense of deja vu!

After an enjoyable day's driving, we could not think of any concerns at all about this extremely competent 4x2 tractor unit. Renault should be shouting from the rooftops about its Premium, as it ticks all the boxes for a much wider range of customers than it was perhaps originally aimed at.

The Renault Premium has evolved incredibly well and is without a doubt up among the front runners on any operational criteria.

* The 2007 Top Truck Award certificate presentation ceremony will be held on the Renault Truck UK stand at the CV Show, Birmingham, in April.